Snort and Sourcefire users are urged to update their intrusion detection software following the discovery of a potentially serious security vulnerability.

A stack-based buffer overflow security bug in the preprocessor handling DCE/RPC traffic means hackers could inject hostile code onto systems running the popular open source Snort package and its commercial equivalent, Sourcefire. Snort versions 2.6.1, 2.6.1.1, 2.6.1.2 and Snort 2.7.0 beta 1 are all vulnerable to the bug.

Intrusion detection software packages are the CCTV cameras of the network security world, recording hacking attacks, and (in some well defined cases) blocking potentially hostile traffic. Worse than simply disabling this protection, the vulnerability creates a means to attack networks using the very tools designed to safeguard them.

Although no exploit code for the vulnerability exists yet, sys admins are encouraged to update to Snort version 2.6.1.3 or to disable the vulnerable DCE/RPC preprocessor as a workaround, in cases where an update is not immediately possible.

Users of Sourcefire are encouraged to apply SEU 64, an update available from the Sourcefire Customer Support website. Users not able to apply this patch need to edit their policies, unchecking the DCE/RPC "Enabled" check box, as a workaround. ®

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