Public Vulnerability Reports

Multiple Vendor FreeType2 PFB Memory Corruption Vulnerability



FreeType2 is an open source library for parsing fonts that is used by many applications. This includes projects such as X.Org, Second Life, GD2, and OpenJDK. For more information, please see the vendor's website at the following URL.


Remote exploitation of a memory corruption vulnerability in the FreeType2 library, as included in various vendors' operating systems, could allow an attacker to execute arbitrary code with the privileges of the affected application.

The vulnerability exists within the code responsible for parsing Printer Font Binary (PFB) format font files. By providing an invalid 'number of axes' in the file, it is possible to cause the code to call the free() function on areas of memory that were not dynamically allocated. This can lead to memory corruption, which can allow for the execution of arbitrary code.


Exploitation of this vulnerability results in the execution of arbitrary code with the privileges of the application using the library. Since FreeType2 is a library and not a standalone application, the exploitation vector will vary. iDefense Labs verified that local privilege escalation was possible via the X.Org Xserver.


iDefense has confirmed the existence of this vulnerability in FreeType2 version 2.3.5. Previous versions may also be affected.


iDefense is currently unaware of any workarounds for this issue. Changing the permissions on the library may not always be effective since applications that run with root privileges are not restricted by file permissions.


The FreeType maintainers addressed this vulnerability with the release of version 2.3.6. For more information, refer to the release notes at the following URL.


The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2008-1807 to this issue. This is a candidate for inclusion in the CVE list (, which standardizes names for security problems.


06/03/2008 Initial vendor notification
06/04/2008 Initial vendor response
06/10/2008 Coordinated public disclosure


This vulnerability was reported to iDefense by regenrecht.

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