ModSecurity < 2.7.6 Chunked Header Filter Bypass

This script is Copyright (C) 2014 Tenable Network Security, Inc.


Synopsis :

The remote web application firewall may be affected by a filter bypass
vulnerability.

Description :

According to its banner, the version of ModSecurity installed on the
remote host is prior to 2.7.6. It is, therefore, potentially affected
by a filter bypass vulnerability.

A filter bypass vulnerability exists with 'modsecurity.c' not properly
handling chunked requests. A remote attacker, with a specially crafted
request, can bypass security filters and inject arbitrary content.

Note that Nessus has not tested for this issue but has instead relied
only on the version in the server's banner.

See also :

https://github.com/SpiderLabs/ModSecurity/releases/tag/v2.7.6
http://martin.swende.se/blog/HTTPChunked.html
http://www.nessus.org/u?88e6187f

Solution :

Upgrade to ModSecurity version 2.7.6 or later.

Risk factor :

Medium / CVSS Base Score : 5.0
(CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N)
CVSS Temporal Score : 4.3
(CVSS2#E:ND/RL:OF/RC:C)
Public Exploit Available : true

Family: Firewalls

Nessus Plugin ID: 73962 ()

Bugtraq ID: 66552

CVE ID: CVE-2013-5705