[security-alerts] FW: [SA18959] Snort frag3 Preprocessor Packet Reassembly Vulnerability

["Kazennov, Vladimir" <Vladimir.Kazennov@xxxxxxxxxx>]

> 
> 
> TITLE:
> Snort frag3 Preprocessor Packet Reassembly Vulnerability
> 
> SECUNIA ADVISORY ID:
> SA18959
> 
> VERIFY ADVISORY:
> http://secunia.com/advisories/18959/
> 
> CRITICAL:
> Moderately critical
> 
> IMPACT:
> Security Bypass
> 
> WHERE:
> From remote
> 
> SOFTWARE:
> Snort 2.4.x
> http://secunia.com/product/5691/
> 
> DESCRIPTION:
> siouxsie has reported a vulnerability in Snort, which potentially can
> be exploited by malicious people to bypass certain security
> restrictions.
> 
> The vulnerability is caused due to an error in the frag3 preprocessor
> which causes snort to skip "ip_option_length" bytes from the end of
> the IP options when reassembling a packet. This can potentially be
> exploited to bypass signature detection via certain specially-crafted
> fragmented packets.
> 
> The vulnerability has been reported in version 2.4.3. Other versions
> may also be affected.
> 
> SOLUTION:
> Filter potentially malicious fragmented IP packets with a firewall.
> 
> PROVIDED AND/OR DISCOVERED BY:
> siouxsie
> 
> ----------------------------------------------------------------------