[Snort-sigs] Sourcefire VRT Certified Snort Rules Update 2011-04-27

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Wed Apr 27 15:06:35 EDT 2011

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Sourcefire VRT Certified Snort Rules Update

The Sourcefire VRT has identified possible issues with two shared
object rules. This release contains modifications to those rules that
fix these potential problems.

A problem has been identified in a shared object rule identified as GID
3 SID 18676. This problem causes Snort to hang in an infinite loop when
the rule is evaluated.


  1. The set of conditions necessary to cause this rule to enter an
     infinite loop require a very unique set of content matches to be
     present in the data being processed. In the unlikely event that
     these conditions occur, the last content match in the set must not
     return true.
  2. This set of conditions is very unlikely to occur in normal,
     non-malicious network traffic.
  3. Additionally, if all the conditions in the rule are met, meaning
     that a malicious set of traffic was detected, then the rule works
     as expected and the infinite loop does not occur.
  4. There are currently no known threats available publicly or in the
     wild for this vulnerability.

Upon review of other custom shared object rule code, a similar issue was
found in GID 3, SID 17665. The VRT has pro-actively fixed that rule.

The modifications to GID 3, SIDs 18676 and 17665 are included in this release.
For a complete list of new and modified rules please see:

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