A vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Office Excel. Exploitation requires that the attacker coerce the target into opening a malicious .XLS file. The specific flaw exists within the parsing of the BIFF file format used by Microsoft Excel. During the processing of a malformed tag a heap allocation can be adversely controlled. When user supplied data is copied to a heap buffer the resulting data results in a arbitrary memory overwrite. If successfully exploited this could lead to system compromise under the credentials of the currently logged in user.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/64515/TPTI-08-03.txt
Source: https://packetstormsecurity.com/files/64515/TPTI-08-03.txt.html