Threats / Microsoft / CVE-2011-3402
CVE-2011-3402
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Microsoft Windows vulnerability
Microsoft Windows kernel TrueType font parsing vulnerability in win32k.sys allows remote code execution through malicious font data embedded in documents or web pages.
Verdict
Today item — known-exploited.
Remote attackers can achieve arbitrary code execution by crafting malicious TrueType font data delivered via Word documents or web content, exploiting a parsing flaw in the Windows kernel-mode font engine.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
10 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-10-06).
Probability (EPSS)
EPSS 0.78285 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Windows. Confirm exact fixed builds in the vendor advisory.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious TrueType font and embed it in a Word document or host it on a web page.
Business
An employee or user downloads and opens the document or visits the compromised web page.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I trigger the vulnerable font parsing code in win32k.sys when the system processes the malicious font data.
Business
The kernel-mode driver processes untrusted font input without proper validation.
3
Lateral reach — past segmentation narrative 3
Attacker
I execute arbitrary code with kernel privileges on the target system.
Business
The attacker gains complete system compromise, enabling data theft, malware installation, or lateral movement.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05