Microsoft Windows Remote Code Execution
CVE-2011-3402 is a high-severity vulnerability in Windows 7 from Microsoft, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. CISA added it to the Known Exploited Vulnerabilities catalogue on October 6, 2025, which means attacks have been observed in the wild.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Windows 7 you run against the affected versions below, and install the vendor's latest release.
- CISA's 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.
- Read the advisory on blogs.technet.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Windows 7 | Not specified in the record | Not stated |
| Microsoft | Windows Server 2003 | Not specified in the record | Not stated |
| Microsoft | Windows Server 2008 | Not specified in the record | Not stated |
| Microsoft | Windows Vista | Not specified in the record | Not stated |
| Microsoft | Windows Xp | Not specified in the record | Not stated |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 3.1 | 8.8 | High | CISA (ADP) |
| CVSS 2.0 | 9.3 | High | NVD |
Official 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."
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: total).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Advisories
- blogs.technet.com/b/msrc/archive/2011/11/03/microsoft-releases-security-advisory-2639658.aspx
- secunia.com/advisories/49121
- secunia.com/advisories/49122
- technet.microsoft.com/security/advisory/2639658
- docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-087
- docs.microsoft.com/en-us/security-updates/securitybulletins/2012/ms12-034
- docs.microsoft.com/en-us/security-updates/securitybulletins/2012/ms12-039
Third-party and government advisories
- isc.sans.edu/diary/Duqu+Mitigation/11950Third Party Advisory
- us-cert.gov/cas/techalerts/TA11-347A.htmlUS Government Resource
- us-cert.gov/cas/techalerts/TA12-129A.htmlUS Government Resource
- us-cert.gov/cas/techalerts/TA12-164A.htmlUS Government Resource
- us-cert.gov/control_systems/pdf/ICS-ALERT-11-291-01E.pdfUS Government Resource
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2011-3402US Government Resource
Other references
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