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Help! I Need to Respond to All These Cisco IOS Software Vulnerabilities and I Cannot Scale!!!

October 23, 2012 at 7:32 am PST

No software is immune to security vulnerabilities. The time between the discovery and disclosure of security vulnerabilities and the availability of an exploit is getting shorter. This imposes pressures on network security professionals and information technology (IT) managers to quickly respond to security vulnerabilities or apply mitigation in their network. Many organizations are struggling to keep up-to-date with the constant release of new vulnerabilities and software fixes. At the same time, they are under pressure to provide near 100% availability of key business services and systems.

Note: Cisco has a very robust vulnerability management process. This process is described in detail at Cisco’s Security Vulnerability Policy. The Cisco Product Security Incident Response Team (PSIRT) manages the receipt, investigation, and public reporting of security vulnerability information that is related to Cisco products and networks.

As an example, every time Cisco discloses a security vulnerability for Cisco IOS Software (or any given product), network security administrators have to identify affected devices and (in numerous cases) upgrade such devices. These activities can take hours, days, or even weeks depending on the size of the organization. For instance large enterprises and organizations may have thousands of routers and switches that need to be assessed for the impact of any given vulnerability.

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Adding Data Segment Cross References in IDA

Recently I was working on reverse engineering a 16-bit MS-DOS binary to better understand a network transport protocol used for modem communication in some software I was looking at. I was using the IDA Pro tool for this purpose.

However, to my dismay, after looking at the string table and finding a string that seemed relevant to the particular section of code which I was interested in, I noticed that none of the strings in the string table contained cross reference information, and I was therefore unable to easily jump to the instructions in which it was used.

Upon further analysis, I determined that the reason the cross reference information for the strings in the table was not populated is because the strings resided in the data segment and referenced using the ds segment register.

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Tracking Malicious Activity with Passive DNS Query Monitoring

Ask anyone in the information security field they will tell you:

Security is not fair. There is essentially an unlimited supply of attackers that can test your defenses with impunity until they eventually succeed.

As a member of the Cisco Computer Security Incident Response Team (CSIRT) I’ve seen this asymmetry up close, so I can tell you that good security is really hard. Besides the normal security practices like deploying firewalls, IDS sensors, antivirus (AV), and Web Security Appliances, CSIRT is increasingly looking to the network as a data source. We have been collecting NetFlow for years but we have always wanted additional context for the flow data. While it is true that the Internet is built on TCP/IP, Internet services—both good and bad—are found by name using the Domain Name System (DNS). For years infosec has been network-address-centric and the attackers have adapted. Today it is very common to see malware command and control (C&C) use domain generation algorithms (DGAs), Peer-to-Peer (P2P), or even fast-flux DNS to evade IP address-based detection and blocking. It has become absolutely clear that to keep up with the latest attacks and attackers you must have a view into the DNS activity on your network.

CSIRT has been struggling with limited DNS information for a while now, so I am pleased to say we finally have comprehensive visibility into the DNS activity on our network. Before I dive into how we tackled this problem I should back up and explain a bit more about DNS…

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SIO Portal: Tell Us What You Think!

The Cisco Security Intelligence Operations (SIO) Portal is the primary outlet for Cisco’s security intelligence and the public home to all of our security-related content. This content ranges from Event Responses () to IntelliShield Alerts () to Cisco product Security Advisories (). The SIO Portal is intended to be the first place you visit when looking for security information from Cisco.

Customer input is very important to us. With this in mind, we’ve launched two new customer listening tools on the SIO Portal: an enhanced feedback mechanism and a short six-question survey.

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Student project collaboration with NC State University

It was about a year ago that Dr. Yannis Viniotis, Professor of the Electrical & Computer Engineering (ECE) department at North Carolina State University (NCSU), met with senior Cisco Engineers and agreed to collaborate on several small, hands-on projects with Cisco Engineers and NCSU students.

The NCSU ECE department partners with the industry as part of their Senior Design Project Program, where various vendors serve as sponsors and offer several projects for NCSU students to complete. That is also how the Cisco-NCSU collaboration started. Students get to work on real networking industry problems guided by engineers that already work in the industry. The students gain experience that can be later used in their professional lives. The Cisco engineers get to work with future engineers, mentoring and preparing them for their professional lives and solving some real world technical challenges. It is fun and educational for both sides.

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