OpenOffice.org has patched a critical vulnerability in the open-source application suite.
The vulnerability concerns the way OpenOffice handles .wmf images. Exploitation of the vulnerability, which affects all but the newest version of OpenOffice, can enable a hacker to perform a buffer overflow and then introduce malicious code to the victim's PC.
Security advisor Secunia rates the vulnerability as "highly critical", and it has urged users to patch their systems.
OpenOffice has uploaded the patch to its website. Users must manually install the file in place of its vulnerable predecessor, or upgrade to the latest version of the software, OpenOffice 2.1. Open-source suppliers such as Red Hat have followed suit by releasing their own patches.
OpenOffice has become increasingly popular as a free alternative to Microsoft's Office suite. It contains all the standard business applications, including word processing, database and spreadsheet programmes.
Although this is the first .wmf vulnerability to hit OpenOffice, such flaws have been a thorn in the side for Windows.
In early 2006, Microsoft acknowledged a critical weakness in the way Windows renders .wmf files, leading to the company releasing patches out of cycle. The UK parliament was attacked at the time using the vulnerability.