[Snort-users] Sourcefire Advisory: Vulnerability in Snort DCE/RPC Preprocessor

Snort Releases snortreleases at ...950...
Mon Feb 19 13:16:54 EST 2007

February 19, 2007


Sourcefire has learned of a remotely exploitable vulnerability in the 
Snort DCE/RPC preprocessor. This preprocessor is vulnerable to a 
stack-based buffer overflow that could potentially allow attackers to 
execute code with the same privileges as the Snort binary. Sourcefire 
has prepared updates for Snort open-source software to address this issue.

This vulnerability has been identified as CVE-2006-5276.

Snort Versions Affected:

* Snort 2.6.1,, and
* Snort 2.7.0 beta 1

This vulnerability also affects Sourcefire commercial products. For 
information and updates for Sourcefire products, please go to the 
Sourcefire support site.

Mitigating Factors:

Users who have disabled the DCE/RPC preprocessor are not vulnerable. 
However, the DCE/RPC preprocessor is enabled by default.

Recommended Actions:

* Open-source Snort 2.6.1.x users are advised to upgrade to Snort (or later) immediately.
* Open-source Snort 2.7 beta users are advised to mitigate this issue by 
disabling the DCE/RPC preprocessor.
   This issue will be resolved in Snort 2.7 beta 2.


Snort users who cannot upgrade immediately are advised to disable the 
DCE/RPC preprocessor by removing the DCE/RPC preprocessor directives 
from snort.conf and restarting Snort. However, be advised that disabling 
the DCE/RPC preprocessor reduces detection capabilities for attacks in 
DCE/RPC traffic. After upgrading, customers should reenable the DCE/RPC 

Detecting Attacks Against This Vulnerability:

Sourcefire will be releasing a rule pack that provides detection for 
attacks against this vulnerability.


What does the update do?
- Snort (or later) removes the vulnerability by correcting the 
buffer overflow condition in the DCE/RPC preprocessor.

Has Sourcefire received any reports that this vulnerability has been 
- No. Sourcefire has not received any reports that this vulnerability 
has been exploited.


Sourcefire would like to thank Neel Mehta from IBM X-Force for reporting 
this issue and working with us to resolve it.

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