Multiple vulnerabilities have been reported in Microsoft Office Excel, which can be exploited by malicious people to compromise a user's system.

1) An error when processing the "SerAuxErrBar" record can be exploited to cause a heap-based buffer overflow via a specially crafted file.

2) An input validation error can be exploited to corrupt memory via a specially crafted file.

3) A use-after-free error when processing the "SST" record can be exploited via a specially crafted file.

4) A boundary error when processing Feature11/Feature12 records can be exploited to cause a stack-based buffer overflow via a specially crafted file.

Successful exploitation of the vulnerabilities allows execution of arbitrary code, but requires tricking a user into opening a malicious file.

Solution
Apply patches.
Further details available to Secunia VIM customers

Provided and/or discovered by
4) An anonymous person via ZDI.

The vendor credits:
1) Sean Larsson via iDefense.
2, 3) An anonymous person via iDefense.

Changelog
Further details available to Secunia VIM customers

Original Advisory
MS12-076 (KB2597126, KB2687307, KB2687311, KB2687313, KB2687481, KB2764047, KB2764048):
http://technet.microsoft.com/en-us/security/bulletin/ms12-076

ZDI:
http://www.zerodayinitiative.com/advisories/ZDI-12-184/

Deep Links
Links available to Secunia VIM customers