A heap-based buffer overflow, leading to array index error was found in the way the Pango font rendering library rendered glyph box for certain FTBitmap objects, when the FreeType2 Pango back end was used for rendering. If an attacker created a specially-crafted font file and tricked a local, unsuspecting user into loading the font file in an application that uses the Pango font rendering library and FreeType2 Pango back end was used for rendering, it could cause that application to crash or, potentially, execute arbitrary code with the privileges of the user running the application.
References: [1] https://bugs.launchpad.net/ubuntu/+source/pango1.0/+bug/696616
CVE Request: [2] http://www.openwall.com/lists/oss-security/2011/01/18/6
Public PoC: [3] https://bugs.launchpad.net/ubuntu/+source/pango1.0/+bug/696616/comments/1 (malicious font) [4] https://bugs.launchpad.net/ubuntu/+source/pango1.0/+bug/696616/comments/2 (sample text file to trigger the crash)