---
title: "CVE-2011-3402: Microsoft Windows Remote Code Execution Vulnerability"
url: https://erroneo.us/security/cve/CVE-2011-3402/
description: "CVE-2011-3402 (Microsoft Windows): Exploited in the wild (CISA KEV). Unspecified vulnerability in the TrueType font parsing engine in win32k.sys in the…"
type: vulnerability-record
section: "Security Digest"
date_published: 2011-11-04
date_modified: 2025-10-22
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2011-3402"
kev: true
cvss: 8.8
epss: 0.78138
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2011-3402: Microsoft Windows Remote Code Execution Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run Microsoft Windows. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-10-06, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-10-27 ; treat that as the outer limit, not the target.
- EPSS 78.1% , percentile 99.6: FIRST’s model estimates a 78.1% chance of exploitation activity in the next 30 days, higher than 99.6% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.

## What it is

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."

## Affected products (CVE record)

- n/a n/a: see advisory

## Severity

- CISA-ADP CVSS 3.1: 8.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: added 2025-10-06; federal due date 2025-10-27. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 78.14% probability of exploitation activity in the next 30 days; percentile 99.6.

## Sources

- [MS11-087](https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-087)
- [MS12-034](https://docs.microsoft.com/en-us/security-updates/securitybulletins/2012/ms12-034)
- [MS12-039](https://docs.microsoft.com/en-us/security-updates/securitybulletins/2012/ms12-039)
- [CVE.org record CVE-2011-3402](https://www.cve.org/CVERecord?id=CVE-2011-3402)
- [NVD entry CVE-2011-3402](https://nvd.nist.gov/vuln/detail/CVE-2011-3402)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2011-3402)
- [49121](http://secunia.com/advisories/49121)
- [oval:org.mitre.oval:def:15645](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A15645)
- [TA12-164A](http://www.us-cert.gov/cas/techalerts/TA12-164A.html)
- [blogs.mcafee.com](http://blogs.mcafee.com/mcafee-labs/the-day-of-the-golden-jackal-%E2%80%93-further-tales-of-the-stuxnet-files)
- [1027039](http://www.securitytracker.com/id?1027039)
- [49122](http://secunia.com/advisories/49122)
- [symantec.com](http://www.symantec.com/content/en/us/enterprise/media/security_response/whitepapers/w32_duqu_the_precursor_to_the_next_stuxnet.pdf)
- [TA11-347A](http://www.us-cert.gov/cas/techalerts/TA11-347A.html)
- [oval:org.mitre.oval:def:13998](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A13998)
- [us-cert.gov](http://www.us-cert.gov/control_systems/pdf/ICS-ALERT-11-291-01E.pdf)
- [securelist.com](http://www.securelist.com/en/blog/208193197/The_Mystery_of_Duqu_Part_Two)
- [technet.microsoft.com](http://technet.microsoft.com/security/advisory/2639658)
- [oval:org.mitre.oval:def:15290](https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A15290)
- [isc.sans.edu](http://isc.sans.edu/diary/Duqu+Mitigation/11950)
- [symantec.com](http://www.symantec.com/connect/w32-duqu_status-updates_installer-zero-day-exploit)
- [TA12-129A](http://www.us-cert.gov/cas/techalerts/TA12-129A.html)
- [blogs.technet.com](http://blogs.technet.com/b/msrc/archive/2011/11/03/microsoft-releases-security-advisory-2639658.aspx)

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Source page: https://erroneo.us/security/cve/CVE-2011-3402/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt