SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2011-3402

Microsoft Windows Remote Code Execution Vulnerability

KEVHIGH 8.8EPSS 78.3%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 27 October 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

Unspecified vulnerability in the TrueType font parsing engine in win32k.sys in the kernel-mode drivers in Microsoft Windows XP SP2 and SP3, Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2, R2, and R2 SP1, and Windows 7 Gold and SP1 allows remote attackers to execute arbitrary code via crafted font data in a Word document or web page, as exploited in the wild in November 2011 by Duqu, aka "TrueType Font Parsing Vulnerability."

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
78.29% probability · 100th percentile
CISA KEV
Listed 6 October 2025 · due 27 October 2025
Affected
microsoft/windows 7 · microsoft/windows server 2003 · microsoft/windows server 2008 · microsoft/windows vista · microsoft/windows xp
Source
secure@microsoft.com

CISA notes

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-087 ; https://nvd.nist.gov/vuln/detail/CVE-2011-3402

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.