Threats / Microsoft / CVE-2021-41357
CVE-2021-41357
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Microsoft Win32k vulnerability
Microsoft Win32k privilege escalation vulnerability exploited in the wild. Allows attackers to elevate privileges on affected Windows systems.
Verdict
Today item — known-exploited.
Unspecified privilege escalation in Win32k with active exploitation observed. Low EPSS score suggests limited weaponization complexity, but real-world exploitation confirms practical threat. Patching recommended.
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
1 independent public report 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 2022-04-25).
Probability (EPSS)
EPSS 0.01968 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Microsoft, Win32k. 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
Execute code with limited privileges on a target Windows system.
Business
Attacker gains foothold on endpoint with user-level access.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
Trigger Win32k vulnerability to escalate privileges to system or administrator level.
Business
Attacker obtains elevated permissions, bypassing access controls.
3
Lateral reach — past segmentation narrative 3
Attacker
Maintain persistence and execute arbitrary operations with elevated rights.
Business
Attacker can install malware, modify system configuration, or access sensitive data across the organization.
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