Microsoft Excel Feature11/Feature12 Record Trusted Counter Remote Code Execution Vulnerability

2012-11-15T00:00:00
ID ZDI-12-184
Type zdi
Reporter Anonymous
Modified 2012-11-09T00:00:00

Description

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Excel. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within Excel's parsing of Feature11/Feature12 records. The process trusts a supplied counter value without validating its size and proceeds to use it within a copy operation to the stack. An attacker can abuse this to execute arbitrary code under the context of the user running Excel.