Outpost24's Expert Security Programmer Anthony de Almeida Lopes discovers libxsl vulnerability

2008-11-14

Anthony de Almeida Lopes, Expert Security Programmer for Outpost24 AB, is credited in discovering a vulnerability in libxsl, which is the de facto standard for open-source XSL processing and is used in many open and closed source applications. Affected vendors include, but are not limited to: Red Hat, Apple, Ubuntu and Mandriva.

Almeida Lopes states, "It's not a vulnerability in a specific application, but a vulnerability in a library that many applications use. The vulnerability is a stack overflow with potential for heap corruption that allows for denial of service and potentially arbitrary code execution."

Within one month, some vendors - including Red Hat, were able to release patches for the vulnerability, while Apple has just recently released Safari 3.2 with the fix on Thursday, November 13th. You can check out the Apple update here.

You can read the GNOME Bugzilla Entry here. And the CVE Advisory here. Red Hat also released a security advisory about the vulnerability, which can be read here.

Anthony de Almeida Lopes is an Expert Security Programmer at Outpost24 AB, in Sweden. His research focuses on novel virus technology development and protection and non-specific exploitation of UNIX systems. In June, he gave a talk at RECON 2008 on "Bypassing Security Protections by Backdooring libc" and in 2006 he gave a talk at RECON on a proof of concept virus that took advantage of the NOP areas in executables generated for x86 UNIX, Windows and MacOS X systems for the purpose of increasing difficulty in detection.

Outpost24 AB's Computer Security Researcher and Software Developer speaking at RECON 2008