Zero-day vulnerability in Microsoft Excel

Memory corruption

The vulnerability has been exploited over a year and was reported to vendor on 2009-03-26.
According to Symantec the first exploitation of the vulnerability was discovered on 2008-07-25.

Known malware:


Vulnerability details

Advisory: SB2009060902 - Multiple vulnerabilities in Microsoft Excel

Vulnerable component: Microsoft Excel

CVE-ID: CVE-2009-1134

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C

CWE-ID: CWE-119 - Memory corruption


The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The weakness exists due to buffer overflow when parsing the Excel spreadsheet file format. A remote attacker can create a specially crafted Excel file containing a malformed record pointer, trick the victim into opening it, trigger memory corruption and execute arbitrary code on the target system with privileges of the current user.

Successful exploitation of the vulnerability results in arbitrary code execution on the vulnerable system.

Note: according to reports this vulnerability was being actively exploited before Microsoft issued security patch.