Threats / Microsoft / CVE-2021-36942
CVE-2021-36942
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Microsoft Windows vulnerability
Microsoft Windows LSA spoofing vulnerability allows unauthenticated attackers to coerce domain controller NTLM authentication to arbitrary servers via LSARPC interface method calls.
Verdict
Today item, not a backlog item.
Critical spoofing flaw enabling credential relay attacks. Actively exploited in ransomware campaigns with EPSS 0.937. Attackers can intercept domain controller authentication to compromise network security and facilitate lateral movement.
CISA KEV Yes · 2021-11-033Ransomware use Flagged3EPSS 0.66023 (verify live)4Exploit Weaponized · public PoC5
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
15 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 2021-11-03), flagged for known ransomware use.
Probability (EPSS)
EPSS 0.66023 — 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.
Weakness (CWE)
Mapped to CWE-749 Exposed Dangerous Method — weakness family: Authorization / access control.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
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 call an unauthenticated method on the LSARPC interface to trigger authentication coercion.
Business
Domain controller authentication is redirected to attacker-controlled server, exposing NTLM credentials.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I relay the captured NTLM authentication to legitimate services for unauthorized access.
Business
Attacker gains elevated privileges and moves laterally across the network infrastructure.
3
Lateral reach — past segmentation narrative 3
Attacker
I deploy ransomware payloads using compromised domain controller credentials.
Business
Organization suffers widespread encryption of critical systems and operational shutdown.
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