# Microsoft Windows: 3 exploited vulnerabilities (CVE-2011-3402, CVE-2013-3918, CVE-2021-43226) · pwn.watch

> CVE-2011-3402: Microsoft Windows Kernel contains an unspecified vulnerability in the TrueType font parsing engine in win32k.sys in the kernel-mode drivers that allows remote attackers to execute arbitrary code via crafted font data in a Word document or web page. CVE-2013-3918: Microsoft Windows contains an out-of-bounds write vulnerability in the InformationCardSigninHelper Class ActiveX control, icardie.dll. An attacker could exploit the vulnerability by constructing a specially crafted webpage. When a user views the webpage, the vulnerability could allow remote code execution. An attacker who successfully exploited this vulnerability could gain the same user rights as the current user. The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization. CVE-2021-43226: Microsoft Windows Common Log File System Driver contains a privilege escalation vulnerability that could allow a local, privileged attacker to bypass certain security mechanisms. Added to CISA KEV on 2025-10-06.

Page: https://pwn.watch/i/microsoft-windows-cve-2011-3402 · generated 2026-10-23T05:24:08.307Z

## Status
- Severity: critical · status: closed · patch: patched
- Product: Microsoft Windows
- Started: 2025-10-06 · closed: 2025-10-06
- CVEs: CVE-2011-3402, CVE-2013-3918, CVE-2021-43226
- Affected: See vendor advisory / CISA notes (versions not always listed in KEV feed)
- Fixed in: See vendor advisory linked in sources

## Follow this incident
- RSS (one item per update): https://pwn.watch/i/microsoft-windows-cve-2011-3402/feed.xml
- JSON Feed: https://pwn.watch/i/microsoft-windows-cve-2011-3402/feed.json
- Full data (timeline, sources, posts, agentBrief): https://pwn.watch/i/microsoft-windows-cve-2011-3402.json
- This file: https://pwn.watch/i/microsoft-windows-cve-2011-3402/llms.txt

## Updates (newest first)
- 2025-10-06: CISA added CVE-2011-3402 to the KEV catalog (due 2025-10-27).
- 2025-10-06: CISA added CVE-2013-3918 to the KEV catalog (due 2025-10-27).
- 2025-10-06: CISA added CVE-2021-43226 to the KEV catalog (due 2025-10-27).

## Fix brief
# Security brief: Microsoft Windows: 3 exploited vulnerabilities (CVE-2011-3402, CVE-2013-3918, CVE-2021-43226)

Source: https://pwn.watch/i/microsoft-windows-cve-2011-3402 · status: closed (closed Oct 6, 2025) · severity: critical · updated Oct 6, 2025

## Patch status
**PATCHED: fixed releases exist. Upgrade to a fixed version.**

## What it is
CVE-2011-3402: Microsoft Windows Kernel contains an unspecified vulnerability in the TrueType font parsing engine in win32k.sys in the kernel-mode drivers that allows remote attackers to execute arbitrary code via crafted font data in a Word document or web page. CVE-2013-3918: Microsoft Windows contains an out-of-bounds write vulnerability in the InformationCardSigninHelper Class ActiveX control, icardie.dll. An attacker could exploit the vulnerability by constructing a specially crafted webpage. When a user views the webpage, the vulnerability could allow remote code execution. An attacker who successfully exploited this vulnerability could gain the same user rights as the current user. The impacted product could be end-of-life (EoL) and/or end-of-service (EoS). Users should discontinue product utilization. CVE-2021-43226: Microsoft Windows Common Log File System Driver contains a privilege escalation vulnerability that could allow a local, privileged attacker to bypass certain security mechanisms. Added to CISA KEV on 2025-10-06.

Severity detail: CVSS 8.8 (CISA ADP, v3.1); actively exploited (CISA KEV); known ransomware use

- Product: Microsoft Windows
- CVE / advisory ids: CVE-2011-3402, CVE-2013-3918, CVE-2021-43226

## Affected versions
- See vendor advisory / CISA notes (versions not always listed in KEV feed)

## Check whether you're affected
No generic command applies (the product is a hosted service, appliance or desktop app). Check the installed version in its admin UI / About screen and compare with the versions above.

## Fix
Upgrade to one of these fixed versions (or later on the same branch):
- See vendor advisory linked in sources

After upgrading, re-run the checks above and redeploy/restart the affected services.

## Latest updates
- Oct 6, 2025: CISA added CVE-2011-3402 to the KEV catalog (due 2025-10-27).
- Oct 6, 2025: CISA added CVE-2013-3918 to the KEV catalog (due 2025-10-27).
- Oct 6, 2025: CISA added CVE-2021-43226 to the KEV catalog (due 2025-10-27).

## Advisories
- [Microsoft advisory: Microsoft Windows](https://docs.microsoft.com/en-us/security-updates/securitybulletins/2011/ms11-087) (Microsoft)
- [Microsoft advisory: Microsoft Windows](https://docs.microsoft.com/en-us/security-updates/securitybulletins/2013/ms13-090) (Microsoft)
- [Microsoft advisory: Microsoft Windows](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-43226) (Microsoft)
- [NVD: CVE-2011-3402](https://nvd.nist.gov/vuln/detail/CVE-2011-3402) (NVD)
- [NVD: CVE-2013-3918](https://nvd.nist.gov/vuln/detail/CVE-2013-3918) (NVD)
- [NVD: CVE-2021-43226](https://nvd.nist.gov/vuln/detail/CVE-2021-43226) (NVD)
- [CISA Known Exploited Vulnerabilities Catalog](https://www.cisa.gov/known-exploited-vulnerabilities-catalog) (CISA)

## Caveats
Derived from CISA KEV JSON feed catalogVersion 2026.10.21. CVSS from the CVE record (cvelistV5). Exact affected/fixed version strings are not always in the KEV record; verify against the vendor advisory URL. startedAt uses dateAdded (exploitation may have begun earlier; many entries are older CVEs newly confirmed as exploited in 2025). KEV says affected products could be end-of-life, so some devices may never get a fix.

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Machine-readable: https://pwn.watch/i/microsoft-windows-cve-2011-3402.json · all incidents: https://pwn.watch/incidents.json. Verify against the vendor advisory before changing production systems.