iDefense Security Advisory 06.11.08 – Local exploitation of an integer overflow vulnerability in the X.Org X server, as included in various vendors’ operating system distributions, could allow an attacker to execute arbitrary code with the privileges of the X server, typically root. The vulnerability exists within the AllocateGlyph() function, which is called from several request handlers in the render extension. This function takes several values from the request, and multiplies them together to calculate how much memory to allocate for a heap buffer. This calculation can overflow, which leads to a heap overflow. iDefense has confirmed the existence of this vulnerability in X server 1.4 included with X.org X11R7.3, with all patches as of 03/01/08 applied. Previous versions may also be affected.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/67208/06.11.08-1.txt
Source: https://packetstormsecurity.com/files/67208/iDEFENSE-Security-Advisory-2008-06-11.1.html