ModSecurity 1.7.4 for Apache 2.x remote off-by-one overflow

[S-Quadra Security Research <research () s-quadra com>]

                S-Quadra Advisory #2004-03-15

Topic: ModSecurity 1.7.4 for Apache 2.x remote off-by-one overflow
Severity: Average
Vendor URL: http://www.modsecurity.org
Advisory URL: http://www.s-quadra.com/advisories/Adv-20040315.txt
Release date: 15 Mar 2004

1. DESCRIPTION

ModSecurity is an open source intrusion detection and prevention engine
for web applications. It supports both branches of the Apache web
server. Please visit http://www.modsecurity.org for more information
about ModSecurity.

2. DETAILS

When directive "SecFilterScanPost" is enabled, ModSecurity checks
incoming POST payloads. In this mode Apache 2.x version of ModSecurity
is vulnerable to off-by-one overflow which could be potentially used by
a remote attacker to execute arbitrary code on a target's web server.

3. FIX INFORMATION

S-Quadra alerted Ivan Ristic (ModSecurity developer) on this issue 09
Feb 2004. Mod_security 1.7.5 which fixes this issue is available.

4. CREDITS

Evgeny Legerov <e.legerov () s-quadra com> is responsible for discovering
this issue.

5. ABOUT

S-Quadra dedicates its substantial knowledge and resources to managing
clients' IT security risks. S-Quadra audits and protection for software
and networks implement pioneering methods and ground-breaking
technologies.

                S-Quadra Advisory #2004-03-15