Microsoft Excel BIFF File Format Cell Record Parsing Memory Corruption Vulnerability

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Office. Exploitation requires that the attacker coerce the target into opening a malicious .XLS file. The specific flaw exists within the parsing of malformed cell comments. When Excel encounters a malformed record it attempts to rebuild the broken meta-data. A flaw in this rebuilding process allows the user to specify critical data offsets eventually leading to code execution under the logged in users credentials.