Timur Yunusov and Alexey Osipov from Positive Technologies discovered that the XML files parser of ModSecurity, an Apache module whose purpose is to tighten the Web application security, is vulnerable to XML external entities attacks. A specially-crafted XML file provided by a remote attacker, could lead to local file disclosure or excessive resources (CPU, memory) consumption when processed. This update introduces a SecXmlExternalEntity option which is Off by default. This will disable the ability of libxml2 to load external entities.

For the stable distribution (squeeze), this problem has been fixed in version 2.5.12-1+squeeze2. For the testing distribution (wheezy), this problem has been fixed in version 2.6.6-6 of the modsecurity-apache package. For the unstable distribution (sid), this problem has been fixed in version 2.6.6-6 of the modsecurity-apache package. We recommend that you upgrade your libapache-mod-security packages.

Mod_security is an Apache module whose purpose is to tighten the Web application security. Effectively, it is an intrusion detection and prevention system for the web server.

libapache-mod-security on Debian Linux

This check tests the installed software version using the apt package manager.

• http://www.debian.org/security/2013/dsa-2659.html

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Updated on 2015-03-25