Zero-Day Advisory

Fortinet Discovers Microsoft Office Excel Memory Corruption Vulnerability


Fortinet's FortiGuard Labs has discovered memory corruption vulnerabilities in Microsoft Office Excel which allows a remote attacker to compromise a system through a malicious document.


FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:

Released Jun 09, 2009
Use the solution provided by Microsoft.

Additional Information

All the three vulnerabilities lie in "excel.exe", which is used when processing an Excel file. A maliciously crafted document may contain a malformed 1) BRAI record (0x1051) or 2) Object record (0x5d) or 3) Formula record (0x06) that when processed, will result in memory corruption and allow a remote attacker to arbitrarily execute code on the victims machine.


Bing Liu of Fortinet's FortiGuard Global Security Research Team

IPS Subscription

Fortinet customers who subscribe to Fortinet's intrusion prevention (IPS) service should be protected against this vulnerability with the appropriate configuration parameters in place. Fortinet's IPS service is one component of FortiGuard Subscription Services, which also offer comprehensive solutions such as antivirus, Web content filtering and antispam capabilities. These services enable protection against threats on both application and network layers. FortiGuard Services are continuously updated by FortiGuard Labs, which enables Fortinet to deliver a combination of multi-layered security intelligence and true zero-day protection from new and emerging threats. These updates are delivered to all FortiGate, FortiMail and FortiClient products. Fortinet strictly follows responsible disclosure guidelines to ensure optimum protection during a threat's lifecycle.