SIEM Deployment - Collecting Logs from Windows Servers

An important step in SIEM deployments is to collect logs from servers on which your infrastructure, applications and middleware run.

The event collection from servers is to be seen in the 2nd step in a 3 step approach in SIEM deployment, first step being network and network security devices and last step being the applications.

Microsoft proposes a well-designed log collection infrastructure with 2 options left to the administrators. Both methods use WinRM protocol and are safer than collecting logs using RPC.

In the first method, the collector server connects to event sources and pulls the logs with the help of a domain user which is added to the Event Log Readers group. This method is known as “Collector Initiated Event Forwarding” in Microsoft world and can be better remembered as PULL method. This is the easier method but does not scale well in large environments and may be inefficient as the collector server should regularly contact event sources whether they have logs to transmit or not.

In the second method, which I will detail more in this article, event sources push logs to a collector server over http or https. This method is known as “Source Initiated Subscription” and can be better remembered as PUSH method. This method scales much better to larger environments and is definitely more secure when https option is used as transmission protocol. This method requires less configuration when configured through Group Policy. However special attention must be paid for the collector server when logs are sent over https, especially about listener configuration as it is not that well documented on Microsoft’s documentation and needs good system administration skills.

EVENT SOURCE CONFIGURATION

First of all, the winrm service should be activated from the command line with winrm quickconfig command.

In the Local Group Policy Editor, under Computer Configuration -> Administrative Templates ->  Windows Components -> Event Forwarding menu, “Configure the server address, refresh interval, and issuer certificate authority of a target Subscription Manager” setting should be configured as below:

            

At this point you can prefer to use http or https protocols to transmit your logs to the collector server. The only difference at the event source is the port numbers used for http and https protocols which are 5985 and 5986 respectively as shown below:

Server=http://Servername.Domain:5985/wsman/Subscription Manager/WEC,Refresh=60

Server=https://Servername.Domain:5986/wsman/Subscription Manager/WEC,Refresh=60

Log sending period is chosen as 60 seconds in these examples.

 Once event forwarding configuration is done, the group policy must be updated with  gpupdate /force command.

 In Local Security Policy screen, audit policy settings under Security Setttings -> Local Policies ->  Audit Policy should be configured. It is recommended to enable logging for both successful and failed attempts for all policy items except “Audit object access”, as this setting may generate too many logs if both successful and failed attempts are logged. I recommend configuring this setting only for failed attempts for the beginning and deciding later according to the criticality of the server.

EVENT COLLECTOR CONFIGURATION

First of all, Windows Event Collector service and WinRM service should be enabled from the command line by using wecutil qc and winrm qc commands respectively.

 After this step, Event Viewer is launched and a new Subscription should be created by right clicking on Subscriptions menu item and selecting Create Subscription or selecting from the menu on the right.

Once the Create Subscription window opens, for source initiated subscriptions settings are configured as below.  These settings largely depend on your own needs however there are real life experiences to follow such as collecting logs in “Hardware Events” destination as logs from this folder are correctly parsed at Arcsight and need no further efforts.

Subscription name: Event collection

Destination log: Hardware Events

Subscription type: Source computer initiated

  

Configuration ends after this step and if there are no problems, like firewall rules blocking the traffic, you should be seeing transferred logs in your target log collection folder. The best way to check if there is a problem or not is to use "Runtime Status" option from the menu on the right.

For more details you can read the Technet article below:

https://msdn.microsoft.com/en-us/library/windows/desktop/bb870973(v=vs.85).aspx

Introduction to Security Event and Log Management

Starting from this article, I will share my experiences and insight on Security Event Management and Log Monitoring. I hope you will find some useful information for yourself in them.

To start with: maybe the most important point to know at the start of a SIEM project is to correctly set the expectations from such project. As very important sums of money and effort are put to these projects, the expectations of several units of your company (not only the IT by the way) may be very high.

So, at the kick-off it is important that you know and make sure that others understand:

• that a SIEM solution is not a big box where different parts of IT throw all their logs until the day they will need it. The importance of “Security” word in SIEM must be underlined. Even though by the very nature of SIEM systems, they are considered as Big Data systems but so far they are only “Big Data like” and maybe they should stay so. Peer Teams in IT should take their time to think which category or type of alerts they have to keep, to find out an anomaly in their own systems or which can be meaningful when it comes together with other piece of information.
•  that sizing is one of the critical steps of SIEM project’s success. A strict sizing in such projects is of course impossible but EPS numbers should be guessed with up to 20% accuracy. After that comes the decision of retention period. Most admins would enjoy seeing what website your colleague in the next cubicle visited a year ago but for an effective forensic analysis, a period from 3 to 6 months is advised to be aimed. A failure in not correctly predicting the storage size may cost you having your critical log data overwritten when you most need it. Not to forget, these numbers are also important for the financials, software licenses and appliances sizes and sometimes even the solution architectures change according to the number of logs to be processed.
• that SIEM projects may be huge and should not be tried to be swallowed at once, your company choke while doing so. A wise approach would be to start with Security and  Network Security systems including but not limited to Firewalls, UTMs, IPSs, VPN boxes, Access Control Systems (Radius, Tacacs+), Web Application Firewalls, DOS protection devices, NACs, Load Balancers, Wireless Controllers and Endpoint Security Systems. After these should follow the Infrastructure components, namely OSs and Middlewares of your critical systems. At the last step, you will finally be ready for integrating your applications, which obviously is the most laborious and time-consuming part as several teams will have to come together and discuss.
• that you should document your project very well. SIEM systems are like those puzzles with thousands of pieces and almost every company cooks that soup to its own taste. The way you collect the logs, reduce them and correlate them largely differs. Without proper documentation, you may have serious problems in roll-outs, troubleshooting and handing it over to somebody else or even outsourcing.
• that even to everybody is into it and the technology is very promising, it is still a reactive solution. It will help your company to discover important breaches, learn from important misconfigurations and mistakes and improve your incident response skills and practices but that is all. Everything still depends on your agile, well-documented and respected incident response procedures… Unless you deploy SIEM as a compliance box or to show off your C-level executives.

      After taking into consideration these important facts, you are ready to start choosing your SIEM product. I will mention about SIEM product selection criteria in my next article, before diving into more detail on implementation.

Perimeter Security Devices Evaluation - Part 1

Firewall (Next Generation Firewall, UTM) Selection Criteria – Part 1

Firewalls and other perimeter defense appliances are the most essential security devices of today's IT infrastructures. Almost all security administrators have their favorite vendor when it comes to the selection of the appropriate device for their environment. I have even seen people supporting vendors and products like supporting a sports team.

I for long times have thought about the criteria to be considered when choosing an appropriate perimeter defense device and this article is the result of it. I am not going to criticise or praise any specific product or vendor, I will just try to give a view of the points that should be considered. One should know that a perimeter device to  be used in an SMB may  (and must) differ from a large enterprise and sectors in which the company operates is another important factor.

So, let’s begin naming those criteria one by one.

Functionality

We all know that the days in which firewalls were used just as IP and port filter ACL devices and session state checkers are over a long ago. Everybody expects more from those devices providing efficiencies in many terms starting by cost and efforts.

But how far should a firewall go with functionalities?

Today most firewall products offer additional functionalities such as Intrusion Prevention, Web Content Filtering (Web Proxy), Remote Connectivity Gateway (SSL VPN), Data Loss Prevention, Malware - Spyware Protection, Security Event Management, Endpoint Protection Console Services and Bot Protection. This list may include other functionalities and capabilities according to different vendors but most common ones are these.

While SMBs would like to have all-in-one solutions and they may be right on their approach, special care must be taken at this point. Licensing is the keyword in the selection of many security products and firewalls are no exception to that. SMBs with low information security maturity levels really should not opt in for too many capabilities as it will not serve them that much other than increasing their Operational Expenditure budgets. I believe the key functionalities to be selected as a minimum should be Next Generation Firewall, Intrusion Prevention, Web Proxy and SSL VPN. Administrators should also pay attention to not to put all the functionalities in one box even though they may have cluster configurations.

Leaving security intelligence for several functions to just one vendor is another risk to be aware of.

For larger enterprises, the pros and cons of selecting a multipurpose perimeter security device is more obvious. From one angle having the least number of devices to manage is very important in a time where collecting logs from a big number of different sources is really  a burden for security administrators not even mentioning the cost and licensing advantages.

However, till what moment we can put different functionalities into the same basket.

Vendors all have different hardware designs for their appliances and even one vendor proposes very different products according to the segments. Having multiple functionalities means that a problem in one function may have damaging effects on other functionalities, even though the processes may be isolated the hardware in most cases is not isolated in many vendors (the cost goes higher if hardware isolation exists). You may have to sacrifice certain capabilities in some situations in favor of others, which is really a not desired situation for most people.

Briefly, adding too much in the same basket has its risks and each enterprise should take its decision independently on that subject. In a world where there are really no standard metrics for measuring the computing power of these  appliance, this is the truth security administrators should face.

My experience on this subject is that more and more enterprise should migrate over security products which have hardware isolation for different functionalities starting from separating the management plane from the data plane. I believe many security administrators at least once faced that annoying situation which prevented them to access their devices in case of a serious problem just because data plane is too busy and consuming all the resources. In today's world resource exhaustion attacks are still a major issue to be resolved and until it is resolved processing cycles must be allocated and consumed very very carefully.

No matter what the size of the company some functions should be very carefully thought of in the selection process. In a company where data classification scheme, data roles (owner, custodian, user, etc.) and responsibilities are not clear Data Loss Prevention functionality should not be added to the list. Basic clear text filtering options are present in most of the products present in the market and can be used for basic needs, whenever needed.

Choosing Endpoint Protection Management functionality on the appliance may be wise if you have an enterprise up to 50 employees. From that number on, it is wiser to use a separate system for such a need than consuming very precious resources which may be attributed to more important security functions.

Final observation on perimeter security devices is the Next Generation Firewall capabilities which may be resumed basically to application (including applets and modules) recognition and domain integration (user recognition). These are the musts of such appliances in today's world and must not be taken lightly. Even the biggest vendors with considerable market share are performing these functionalities on the paper, which actually means that they are not performing those functionalities in a stable manner or simply just pretend to do it. In many products they say that the appliance recognizes thousands of applications while in fact those thousands of applications consist of different social media modules and old chat programs. The most needed and critical business applications ( ERP, CRM, Database, Productivity suites) are not recognized and they give you no insight about your business critical data flow.

CISSP - Passed exam in 2 months and at the 1st attempt

My journey to get CISSP certification started with my wish to prove my experience and competency on Information Security, almost a year ago.

My first decision was to get CISM certification which by its name is for people who aim to be “Information Security Manager”s. I did my research, adhered to ISACA and the local chapter and ordered the book. Once the book in hand I was very enthusiastic to get to know what is inside the book and my first disappointment dates back that moment. It was a book of 250 pages, very dry and not really for a person coming from a technical background. During the first week, my record was 4 pages before sleeping on the book and that for 6 days on a row. Plus after that week I almost retained nothing from what I read that far, so I decided to take things a bit easier.

When sharing my experiences with a colleague, he told me about CISSP which seemed to be a more complete program both covering the technical aspects of Information Security and Information Security Management. When I read more about CISSP, I was convinced that giving CISSP the first chance would be a better idea and I very slowly started reading about it.

An interesting series of events made me leave the company I was working for, creating the ideal environment for me to spend more time on my personal development, including the certifications for which I was really not able to spare time and focus. So I started studying seriously for CISSP by the beginning of March 2014.

At the beginning finding the correct resources to study was very important. There are tons of resources both for studying and for practice tests and if you are like me which means if you always want to be 150% sure of what you are doing, that may be very confusing. Techexams.Net Forum on CISSP was a great place to follow as many people who were about to pass the exam and who already passed it share their experiences, creating a very nice community. I would definitely suggest you to follow that forum if you need guidance or a second opinion (even if you do not need anything, go and read! :) )

After reading people’s comments, I decided to use the famous All in one (AIO) 6th Edition book from Shon Harris to study. Many people find that book overly detailed, dry and containing bad humor (I personally would not be that harsh) but like it or not, the book explains everything you need for CISSP easy enough for a 5 years old (That’s the way I like it, that’s a shame but I assume). I can even say that although many people insist that the best resource for CISSP is naturally the ISC²’s Official Guide, the bible of CISSP is the AIO book. You can definitely count on it and use solely that book to pass the exam… If only you have too much time and that much of interest in detail, which I did not have (both).

At that moment Eric Conrad’s CISSP Study Guide 2^nd Edition came as a life saver, which is half the pages AIO makes and a lot easier to read with very nice examples (I will never forget the example about Object Oriented Programming concepts thanks to that perfect example). That book helped me to cover all of the 10 domains in a month.

So by the beginning of April, I was finally able to test myself with practice tests covering questions from all domains to give me an overall opinion, which also encouraged me to take some full length practice tests in a very short period. So basically what I have done during April was to do a full length test per day at least and then evaluate the wrong answers to understand why I was mistaken. Surprisingly from the beginning till the end no matter what test engine I used I was constantly getting scores in 79% and 81% range. By mid-April, I was confident enough to schedule the test for the last week of April or the first week of May. Some domains were really tough for me because I did not have specific work experience on those domains (Almost nobody can have I believe) and the reasoning behind some choices was not logical and clear. You will also meet such situations quite often. My advice is to listen to yourself built from your proper real life experiences and  the voice of common sense in such situations, instead of what book A or book B says (There are surprisingly many points that they disagree, that’s also why using more than 2 books is distracting and confusing).

Be careful about selecting the date and the test center because as in my situation, you make your plans to take the exam next week without doing any arrangements (of course doing arrangements is a bit scary, exam costs 520 euros or USD, that is nothing to joke) and find out that the only test center in your city is fully booked for next 2 months.

So finally made up my mind and booked the test in the nearest city for the first week of May. No matter how much you study, after reading the experiences of many different people with totally different experiences and background, without taking the exam once, you will never be sure enough.

Many people who took the exam say having the managerial (high level) mindset dealing with the questions is essential and most of the questions are long and scenario based…I do respect them but that is not what I think. First of all, in my short working experience of 10 years, I have never seen a manager interested with such level of technical details; most of the stuff in the exam are very technical indeed. And secondly, to my opinion scenario based questions are not like what you have seen in AIO book, very short and easy to get ones and only cover very limited part of the exam, so relax.

Finally I went to the nearest city (500 kms away) and entered the exam. At the end of 20 questions, I already knew that I was going to pass because it was not that much different from what I have seen in practice tests. I was already thinking about my blog entry about passing the exam during the exam, which I would not suggest to anyone :). It took me 4 hours to answer 250 questions in one round and 30 more minutes to revise 25 flagged questions, including the breaks. One’s ability to handle questions greatly decrease along the exam, in the last 30 questions or so, I remember myself reading the same short question 3 or 4 times. If your proctor is not an annoying person, take a break of at least 5 minutes for every hour. What I mentioned is even more valid for those whose native language is not English. Time to answer a question literally increases exponentially. My right eye was f..ked off after carefully staring at the screen for almost 5 hours and I still had 5 hours to drive back to home at night.

So to resume, if someone asked me a prescription for passing the exam I would say:

Read

1. AIO 6^th Edition from Shon Harris (Do all the tests in the book)
2. CISSP Study Guide 2^nd Edition from Eric Conrad (Again do all the tests)

Study

Equivalent of 150 hours including the reading sessions at least in dedicated mode (another clue :) )

Practice

1. Software included in AIO book (Total Tester, the best resource IMHO)
2. Eric Conrad’s 2 Free Full Length Tests
3. Cccure.org’s paid practice tests (Just because every else does it IMHO)
4. McGraw Hill’s free practice tests

Know

Cornerstone concepts that one sees everywhere and every day such as Business Impact Analysis, System Development Life Cycle, BCP/DRP, Incident Response Plan, Risk Analysis and Assessment. Do not memorize the steps but know the flow, the logical order.

Don’t

Memorize the Orange Book levels :)

I wish all of you good luck in your quests to pass the exam and I will definitely keep my blog live with Information Security related article which can be useful for CISSP preparation.

CISSP - EAP Protocols

Questions about EAP are annoying ones, at least for me and not many people really seem to know the difference. Furthermore, even the official CISSP guide from ISC2 does not tell much about them. However you can meet many questions about it in different tests.

I will try to give you the essentials about them so that you also know enough about it and discover more if you wish.

First of all, Extensible Authentication Protocols are created for 802.1x protocol, which aims to provide identity based authentication services. In a secure network environment both client who wants to connect to the corporate network and the network authentication server should properly authenticate each other.

When we speak about mutual authentication, the best way to do is digital certificates and the use of Public Key Infrastructure. Both client and server present their digital certificates to each other for authentication and sometimes use these certificates to build an SSL tunnel to exchange more information.

EAP-TLS (Transport Layer Security) requires both client and the authentication server to use digital certificates for authentication. This method is laborious and expensive as it requires too much effort for the proper management of the certificates mostly on the client side. If the client certificate is not renewed correctly or certificate store is not properly managed, clients may end up having problems connecting the network. Because many network administrators are not quite interested about PKI, troubleshooting is also painful.

EAP-TTLS (Tunneled TLS) eases the problems that EAP-TLS create by eliminating the client side certificates. The server side certificate is used to establish a secure SSL tunnel between client and authentication server and authentication information is shared over this tunnel. This method is of course less secure than EAP-TLS but it is also much easier to configure and maintain.

EAP-PEAP (Protected EAP) works just as the same way EAP-TLS that why it is confusing for me and many others I believe. After the establishment of the secure tunnel using the server certificate, a second method such as EAP-TLS or EAP-MSCHAPv2 (Microsoft’s flavor of EAP) can be used for authentication information.

These are all the methods given in the official guide. There are of course other protocols such as LEAP (Cisco’s first protocol of EAP, now considered insecure and no longer used), EAP-MD5 (Sending authentication information hashed with MD5, much less secure than those mentioned above) and EAP-MSCHAPv2 (just an inner authentication method after the first 3, authenticating using Active Directory credentials), but these are considered not essential it seems. It is good to know just that much about them for general knowledge and the exam.

I know Aaron Woland from Cisco Networkers events, he is one of the guys who designed Cisco’s famous ISE product and periodically speaks about Identity-based networking concepts and AAA in events. You can find a more detailed explanation in his blog following this link : 

http://www.networkworld.com/community/blog/what-eap-types-do-you-need-identity-projects

CISSP - Between the lines facts on Access Control

Access Control domain is considered as one of the top 5 domains of CISSP CBK and must be paid well attention. In this domain also, there are some concepts that an average IT professional is pretty unfamiliar and which should be well understood to obtain the certification. Markup languages and their use can be the best example for such concepts.

A subject is an active entity and an object is a passive entity.

Permission refers to the access granted for an object like read, creat,edit and delete.

Right refers to the ability to take an action on an object. E.g. Modify system time.

Privilege = permission + right

A directive access control is deployed to direct, confine, or control the actions of subjects to force or encourage compliance with security policies.

A cognitive password is usually a series of questions about facts or predefined responses that only the subject should know. For example, what is your mother’s maiden name?

DAC is also referred to as identity-based access control because access is granted to subjects based on their identity.

A DAC model is implemented using access control lists (ACLs) on objects. It does not offer a centrally controlled management system because owners can alter the ACLs on their objects at will. Access to objects is easy to change, especially when compared to the static nature of mandatory access controls.

Within a DAC environment, users’ privileges can easily be suspended while they are on vacation, resumed when they return, or terminated when they leave.

Administrators centrally administer non-discretionary access controls and can make changes that affect the entire environment.

In a non-DAC model, access does not focus on user identity. Instead, a static set of rules governing the whole environment is used to manage access. Non-DAC systems are centrally controlled and easier to manage (although less flexible). Rule-based access controls and lattice-based access controls are both considered non-discretionary.

Subjects under lattice-based access controls acquire a least upper bound and a greatest lower bound of access to labeled objects based on their assigned lattice positions. A common example of a lattice-based access control is a mandatory access control.

A mandatory access control (MAC) system relies upon the use of classification labels. Each classification label represents a security domain, or a realm of security. A security domain is a collection of subjects and objects that share a common security policy.

Mandatory access controls are often considered to be non-discretionary controls because they are lattice based. However, the CISSP CIB lists them separately.

An expansion of this access control method is known as need to know. Subjects with specific clearance levels are granted access to resources only if their work tasks require such access.

Mandatory access control is prohibitive rather than permissive, and it uses an implicit deny philosophy. If access is not specifically granted, it is forbidden. It is generally recognized as being more secure than DAC, but it isn’t as flexible or scalable.

A distinguishing factor between MAC and rule-based access controls is that MAC controls have labels while the non-discretionary rule-based access controls do not use labels.

Objects have security labels (or sensitivity labels), subjects have clearances.

A capability table specifies the access rights a certain subject possesses pertaining to specific objects. A capability table is different from an ACL because the subject is bound to the capability table, whereas the object is bound to the ACL.

An access control matrix is a table of subjects and objects indicating what actions individual subjects can take upon individual objects. This type of access control is usually an attribute of DAC models. The access rights can be assigned directly to the subjects (capabilities) or to the objects (ACLs).

A meta-directory gathers the necessary information from multiple sources and stores it in one central directory. This provides a unified view of all users’ digital identity information throughout the enterprise.

A virtual directory plays the same role and can be used instead of a meta-directory. The difference between the two is that the meta-directory physically has the identity data in its directory, whereas a virtual directory does not and points to where the actual data reside.

Web portals functions are parts of a website that act as a point of access to information. A portal presents information from diverse sources in a unified manner.

A web portal is made up of portlets, which are pluggable user-interface software components that present information from other systems. A portlet is an interactive application that provides a specific type of web service functionality.

XML is a common language used to exchange information.

Security Assertion Markup Language (SAML) is an XML-based language that is commonly used to exchange authentication and authorisation (AA) information between federated organisations. It is often used to provide SSO capabilities for browser access.

When there is a need to allow a user to log in one time and gain access to different and separate web-based applications, the actual authentication data have to be shared between the systems maintaining those web applications securely and in a standardized manner. This is the role that the SAML plays. It is an XML standard that allows the exchange of authentication and authorization data to be shared between security domains.

The Service Provisioning Markup Language (SPML) allows for the exchange of provisioning data between applications, which could reside in one organization or many. SPML allows for the automation of user management (account creation, amendments, revocation) and access entitlement configuration related to electronically published services across multiple provisioning systems. This markup language allows for the integration and interoperation of service provisioning requests across various platforms. When a new employee is hired at a company, that employee usually needs access to a wide range of systems, servers, and applications. Setting up new accounts on each and every system, properly configuring access rights, and then maintaining those accounts throughout their lifetimes is time-consuming, laborious, and error-prone. What if the company has 20,000 employees and thousands of network resources that each employee needs various access rights to? This opens the door for confusion, mistakes, vulnerabilities, and a lack of standardization. SPML allows for all these accounts to be set up and managed simultaneously across the various systems and applications. SPML is made up of three main entities: the Re-questing Authority (RA), which is the entity that is making the request to set up a new account or make changes to an existing account; the Provisioning Service Provider (PSP), which is the software that responds to the account requests; and the Provisioning Service Target (PST), which is the entity that carries out the provisioning activities on the requested system.

Transmission of SAML data can take place over different protocol types, but a common one is Simple Object Access Protocol (SOAP). SOAP is a specification that outlines how information pertaining to web services is exchanged in a structured manner. It provides the basic messaging framework, which allows users to request a service and, in exchange, the service is made available to that user. Let's say you need to interact with your company's customer relationship management (CRM) system, which is hosted and maintained by the vendor—for example, Salesforce.com. You would log in to your company's portal and double-click a link for Salesforce. Your company's portal will take this request and your authentication data and package it up in an SAML format and encapsulate that data into a SOAP message. This message would be transmitted over an HTTP connection to the Salesforce vendor site.

The use of web services in this manner also allows for organizations to provide service oriented architecture (SOA) environments. An SOA is a way to provide independent services residing on different systems in different business domains in one consistent manner. For example, if your company has a web portal that allows you to access the company's CRM, an employee directory, and a help-desk ticketing application, this is most likely being provided through an SOA. The CRM system may be within the marketing department, the employee directory may be within the HR department, and the ticketing system may be within the IT department, but you can interact with all of them through one interface.

Extensible Access Control Markup Language (XACML) is used to define access control policies within an XML format, and it commonly implements role-based access controls. It helps provide assurances to all members in a federation that they are granting the same level of access to different roles.

Diameter supports a wide range of protocols, including traditional IP, Mobile IP, and Voice over IP (VoIP). Because it supports extra commands, it is becoming popular in situations where roaming support is desirable, such as with wireless devices and smart phones.”

Key steps in risk management are as follows:

• Identifying assets
• Identifying threats
• Identifying vulnerabilities

After identifying and prioritizing assets, an organization attempts to identify any possible threats to the valuable systems. Threat modelling refers to the process of identifying, understanding, and categorizing potential threats. A goal is to identify a potential list of threats to these systems and to analyze the threats.

Access aggregation refers to collecting multiple pieces of non-sensitive information and combining (aggregating) them to learn sensitive information. Reconnaissance attacks are access aggregation attacks.

A birthday attack focuses on finding collisions. It is so named based on a statistical phenomenon known as the birthday paradox. The birthday paradox states that if there are 23 people in a room, there is a 50 percent chance that any two of them will have the same birthday.

Birthday attacks are mitigated by using hashing algorithms with a sufficient number of bits to make collisions computationally infeasible. There was a time when MD5 (using 128 bits) was considered to be collision free. However, computing power continues to improve, and MD5 is no longer considered safe against collisions. SHA-2 can use as many as 512 bits and is considered safer against birthday attacks and collisions—at least for now.

A drive-by download is a type of malware that installs itself without the user’s knowledge when the user visits a website. Drive-by downloads take advantage of vulnerabilities in browsers or plug-ins.

Network Segregation, perimeter security, control zone and cabling are physical controls.

Extended TACACS (XTACACS) separates authentication, authorization and accounting processes.

Employing a password generator is a bad idea as users will write down difficult passwords somewhere.

Two factor authentication is better than biometric authentication alone.

In Windows environments, administrators can use a Syskey utility that encrypts the database storing the passwords with a locally stored system key.

Signature dynamics is a method that captures the electrical signals when a person signs a name. Keystroke dynamics captures electrical signals when a person types a certain phrase.

A passphrase is a sequence of characters that is longer than a password and, in some cases, takes the place of a password during an authentication process. The user enters this phrase into an application, and the application transforms the value into a virtual password, making the passphrase the length and format that is required by the application.

A memory card holds information but cannot process information. A smart card holds information and has the necessary hardware and software to actually process that information.

Two types of contactless smart cards are available: hybrid and combi. The hybrid card has two chips, with the capability of utilizing both the contact and contactless formats. A combi card has one microprocessor chip that can communicate to contact or contactless readers.

ISO/IEC standard for Smart Cards is ISO/IEC 14443.

Attackers often delete audit logs that hold this incriminating information. Deleting specific incriminating data within audit logs is called scrubbing.

CISSP - Between the lines notes about Telecommunications Security

Telecommunications and Network Security domain is one of the largest domains in CISSP CBK. Even people with important level of experience with network operations may find many points they miss during their daily lives.

In this blog entry, rather than explaining the facts that most people know, I tried to resume those little points that may have missed from many people’s attention up to now. These points may be lifesaving in answering questions. So let’s start with some information about Session Layer which network and security people maybe pay the less attention.

When two applications need to communicate or transfer data between themselves, a connection may need to be set up between them. The session layer is responsible for establishing a connection between the two applications, maintaining it during the transfer of data, and controlling the release of this connection. The session layer works in three phases: connection establishment, data transfer, and connection release.

Session layer protocols control application-to-application communication, whereas the transport layer protocols handle computer-to-computer communication. For example, if you are using a product that is working in a client/server model, in reality you have a small piece of the product on your computer (client portion) and the larger piece of the software product is running on a different computer (server portion). The communication between these two pieces of the same software product needs to be controlled, which is why session layer protocols even exist. Session layer protocols take on the functionality of middleware, which allows software on two different computers to communicate.

Session layer protocols provide interprocess communication channels, which allow a piece of software on one system to call upon a piece of software on another system without the programmer having to know the specifics of the software on the receiving system. The programmer of a piece of software can write a function call that calls upon a subroutine. The subroutine could be local to the system or be on a remote system. If the subroutine is on a remote system, the request is carried over a session layer protocol. The result that the remote system provides is then returned to the requesting system over the same session layer protocol. This is how RPC works.

One security issue common to RPC (and similar interprocess communication software) is the lack of authentication or the use of weak authentication. Secure RPC can be implemented, which requires authentication to take place before two computers located in different locations can communicate with each other. Authentication can take place using shared secrets, public keys, or Kerberos tickets. Session layer protocols need to provide secure authentication capabilities.

RPC and similar distributed computing calls usually only need to take place within a network; thus, firewalls should be configured so this type of traffic is not allowed into or out of a network.

Some protocols that work at session layer are SQL, NetBIOS, NFS, and (RPC).

The main protocols that work at layer 4 are TCP, UDP, SSL, TLS and SPX.

ICMP and IGMP are Layer 3 protocols.

RARP, PPP, PPTP, L2TP, SLIP, ATM, Ethernet, Token Ring and FDDI are Layer 2 protocols.

ISDN, DSL and SONET are Layer 1 protocols.

Port numbers up to 1023 (0 to 1023) are called well-known ports. Ports 0 to 1023 can be used only by privileged system or root processes.

Registered ports are 1024 to 49151, which can be registered with ICANN for a particular use.

Dynamic ports are 49152 to 65535 and are available to be used by any application on an “as needed” basis.

The SYN proxy is a piece of software that resides between the sender and receiver and only sends on TCP traffic to the receiving system if the TCP handshake process completes successfully.

If an attacker can correctly predict the TCP sequence numbers that two systems will use, then she can create packets containing those numbers and fool the receiving system into thinking that the packets are coming from the authorized sending system. She can then take over the TCP connection between the two systems, which is referred to as TCP session hijacking.

802.1AE (MACSec) defines a security infrastructure to provide data confidentiality, data integrity, and data origin authentication. Where a VPN connection provides protection at the higher networking layers, MACSec provides hop-by-hop protection at layer 2.

802.1AR standard specifies unique per-device identifiers (DevID, PKI, certificates) and the management and cryptographic binding of a device (router, switch, access point) to its identifiers.

DHCP packet types are Discover, Offer, Request and Acknowledgment (DORA) in their order.

In environments that require extensive security, wires are encapsulated within pressurized conduits so if someone attempts to access a wire, the pressure of the conduit will change, causing an alarm to sound and a message to be sent to the security staff.

CSMA/CA will send out a message indicating to all other systems that it is going to put data on the line and CSMA/CD will listen to the wire and try to figure out when would be the best time to put data on the line.

Token Ring uses a token-passing technology with a star-configured topology. Each computer is connected to a central hub, called a Multistation Access Unit (MAU). Token ring operates either at 4 or 16 Mbps.

FDDI has a data transmission speed of up to 100 Mbps and is usually used as a backbone network. FDDI also provides fault tolerance by offering a second counter-rotating fiber ring. The primary ring has data traveling clockwise and is used for regular data transmission. The second ring transmits data in a counterclockwise fashion and is invoked only if the primary ring goes down.

Copper Distributed Data Interface (CDDI) can work over UTP cabling. Whereas FDDI would be used more as a MAN, CDDI can be used within a LAN.

Devices that connect to FDDI rings fall into one of the following categories:

• Single-attachment station (SAS) Attaches to only one ring (the primary) through a concentrator
• Dual-attachment station (DAS) Has two ports and each port provides a connection for both the primary and the secondary rings
• Single-attached concentrator (SAC) Concentrator that connects an SAS device to the primary ring
• Dual-attached concentrator (DAC) Concentrator that connects DAS, SAS, and SAC devices to both rings

Loki is actually a client/server program used by hackers to set up back doors on systems and uses ICMP packets to carry control traffic.

The Ping of Death attack is based upon the use of oversized ICMP packets. If a system does not know how to handle ICMP packets over the common size of 65,536 bytes, then it can become unstable and freeze or crash.

In Smurf attack, the attacker sends an ICMP ECHO REQUEST packet with a spoofed source address of victim to victim’s network broadcast address. This means that each system on the victim’s subnet receives an ICMP ECHO REQUEST packet. Each system then replies to that request with an ICMP ECHO REPLY packet to the spoof address provided in the packets—which is the victim’s address.

Fraggle attack works with the same principle with Smurf but Fraggle uses the UDP protocol, and Smurf uses the ICMP protocol. They are both DDoS attacks.

In teardrop attack malformed fragments are created by the attacker, and once they are reassembled, they could cause the victim system to become unstable.

Within DNS servers, DNS namespaces are split up administratively into zones. One zone may contain all hostnames for the marketing and accounting departments, and another zone may contain hostnames for the administration, research, and legal departments. The DNS server that holds the files for one of these zones is said to be the authoritative name server for that particular zone. A zone may contain one or more domains, and the DNS server holding those host records is the authoritative name server for those domains.

The primary and secondary DNS servers synchronize their information through a zone transfer. After changes take place to the primary DNS server, those changes must be replicated to the secondary DNS server. It is important to configure the DNS server to allow zone transfers to take place only between the specific servers. Unauthorized zone transfers can take place if the DNS servers are not properly configured to restrict this type of activity.

DNSSEC implements PKI and digital signatures, which allows DNS servers to validate the origin of a message to ensure that it is not spoofed and potentially malicious.

Organizations should implement split DNS, which means a DNS server in the DMZ handles external hostname-to-IP resolution requests, while an internal DNS server handles only internal requests. This helps ensure that the internal DNS has layers of protection and is not exposed by being “Internet facing.” The internal DNS server should only contain resource records for the internal computer systems, and the external DNS server should only contain resource records for the systems the organization wants the outside world to be able to connect to.

Cybersquatters, individuals who register prominent or established names, hope to sell these later to real-world businesses that may require these names to establish their online presence (Domain grabbing).

IMAP provides all the functionalities of POP, but has more capabilities. If a user is using POP, when he accesses his mail server to see if he has received any new messages, all messages are automatically downloaded to his computer. Once the messages are downloaded from the POP server, they are usually deleted from that server, depending upon the configuration. POP can cause frustration for mobile users because the messages are automatically pushed down to their computer or device and they may not have the necessary space to hold all the messages. This is especially true for mobile devices that can be used to access e-mail servers. This is also inconvenient for people checking their mail on other people’s computers.

POP is commonly used for Internet-based e-mail accounts (Gmail, Yahoo!, etc.), while IMAP is commonly used for corporate e-mail accounts.

E-mail spoofing is a technique used by malicious users to forge an e-mail to make it appear to be from a legitimate source.

If source routing is allowed, the packets contain the necessary information within them to tell the bridge or router where they should go. The packets hold the forwarding information so they can find their way to their destination without needing bridges and routers to dictate their paths.

External devices and border routers should not accept packets with source routing information within their headers, because that information will override what is laid out in the forwarding and routing tables configured on the intermediate devices. Source routing can be used by attackers to get around certain bridge and router filtering rules.

A phreaker is a phone hacker.

Main charachteristics of different types of firewalls are :

• Packet Filters:(Network Layer) Looks at source and destination addresses, ports and services requested. Routers using ACLs to network monitor traffic.
• Application-level Proxy:(Application Layer) Looks deep into packets and makes granular access control decisions. Requires one proxy per protocol.
• Circuit-level Proxy:(Session Layer) Looks only at the header packet information. It protects a wider range of protocols and services than an application-level proxy, but does not provide the detailed level of control available to ALPs.
• Stateful : (Network Layer) Looks at the state and context of packets. Keeps track of each connection using a state table.
• Kernel Proxy : (Application Layer) Faster because processing is done in the kernel. One network stack is created for each packet.

Characteristics of application-level proxy firewalls:

• Each protocol that is to be monitored must have a unique proxy.
• Provides more protection than circuit-level proxy firewalls.
• Require more processing per packet and thus are slower than a circuit-level proxy firewall.

Characteristics of circuit-level proxy firewalls:

• Do not require a proxy for each and every protocol.
• Do not provide the deep-inspection capabilities of an application layer proxy.
• Provide security for a wider range of protocols.

SOCKS is an example of a circuit-level proxy gateway that provides a secure channel.

A system is considered a bastion host if it is a highly exposed device that is most likely to be targeted by attackers.

Firewall rules that should be implemented are as follows:

• Silent rule :  Drop “noisy” traffic without logging it. This reduces log sizes by not responding to packets that are deemed unimportant.
• Stealth rule :  Disallows access to firewall software from unauthorized systems.
• Cleanup rule : Last rule in rule-base that drops and logs any traffic that does not meet preceding rules.
• Negate rule: Used instead of the broad and permissive “any rules.” Negate rules provide tighter permission rights by specifying what system can be accessed and how.

A reverse proxy server is commonly on the network that fulfills clients’ requests; thus, it is handling traffic that is entering its network. The reverse proxy can carry out load balancing, encryption acceleration, security, and caching.

On a smaller scale, companies may choose to implement tarpits, which are similar to honeypots in that they appear to be easy targets for exploitation.

Vishing is voice phishing by the use of voice mail messages and other things.

The main protocols that make up the IPsec suite and their basic functionality are as follows:

• Authentication Header (AH) provides data integrity, data origin authentication, and protection from replay attacks.
• Encapsulating Security Payload (ESP) provides confidentiality, data-origin authentication, and data integrity.
• Internet Security Association and Key Management Protocol (ISAKMP) provides a framework for security association creation and key exchange.
• Internet Key Exchange (IKE) provides authenticated keying material for use with ISAKMP.

AH and ESP can be used separately or together in an IPsec VPN configuration.

• PPTP is used when a PPP connection needs to be extended through an IP-based network.
• L2TP is used when a PPP connection needs to be extended through a non IP-based network.
• IPsec is used to protect IP-based traffic and is commonly used in gateway to gateway connections.
• SSL VPN is used when a specific application layer traffic type needs protection. 

The three core deficiencies with WEP are the use of static encryption keys, the ineffective use of initialization vectors, and the lack of packet integrity assurance.

LEAP (Lightweight Extensible Authentication Protocol) is a Cisco-proprietary protocol released before 802.1X was finalized. LEAP has significant security flaws and should not be used.

EAP-TLS (EAP-Transport Layer Security) uses PKI, requiring both server-side and client side certificates. EAP-TLS establishes a secure TLS tunnel used for authentication. EAP-TLS is very secure due to the use of PKI, but is complex and costly for the same reason. The other major versions of EAP attempt to create the same TLS tunnel without requiring a client-side certificate.

EAP-TTLS (EAP-Tunneled Transport Layer Security) simplifies EAP-TLS by dropping the client-side certificate requirement, allowing other authentication methods (such as password) for client-side authentication. EAP-TTLS is thus easier to deploy than EAP-TLS, but less secure when omitting the client-side certificate.

PEAP (Protected EAP) It is similar to (and may be considered a competitor to) EAP-TTLS, including not requiring client-side certificates.

802.11b uses DSSS, 802.11a uses OFDM and works in the 5GHz frequency band. But working at higher frequency means a device’s signal cannot cover as wide a range.

802.16 is WiMAX.

Bluejacking and Bluesnarfing are Bluetooth attacks.

War driving is the type of attack when one or more people either walk or drive around with a wireless device equipped with the necessary equipment and software with the intent of identifying APs and breaking into them.

The protocol field of the IP packet dictates what protocol the IP packet is using. TCP=6, ICMP=1, UDP=17, IGMP=2

Dedicated point-to-point protocols are HDLC and PPP.

Packet-switched protocols are X.25, Frame Relay and ATM.

Circuit-switched protocols are ISDN and Leased Line.

HDLC provides a higher throughput and supports full-duplex transmissions comparing to SDLC. IBM Mainframe systems used SDLC.

DSL is considered as an “always on” technology.

Footprinting is a method used by an attacker to learn information about a victim before carrying out scanning and probing activity.

802.2 is LLC and 802.3 is MAC. LLC communicates with Layer 3.

SNMP community string is a password a manager uses to request data from the agent.

In PPP protocol, LCP establishes, configures and maintains the connection and NCPs are used for network layer protocol configuration and authentication.