Patchfirst
CVE-2021-31955 KEVPublic exploit Medium · 5.5 EPSS 81.1%

Microsoft Windows Kernel Information Disclosure Vulnerability

Microsoft · Windows

Summary

A flaw in the Windows Kernel component of Microsoft Windows allows sensitive system information to be exposed to an unauthorized control sphere. An attacker needs local access and low-privilege authentication to the system, with no user interaction required, and the exposure impacts confidentiality only.

Official description · NVD

Windows Kernel Information Disclosure Vulnerability

Breakdown
66.8 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
4/15

How an attack unfolds

Based on mappings. Select a step to see the evidence.
  1. How attackers get in

First seen exploited 55 days before it was disclosed. Public exploit code (PoC-in-GitHub) appeared 18 days after disclosure.

  1. First seen exploitedVulnCheck KEV evidence55 days before
  2. Disclosedday 0
  3. Public exploit codePoC-in-GitHub+18 days
  4. Added to CISA KEVEU database agrees+5 mo

CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.

techniques

1 , grouped by in kill-chain order, 1 cited passage 1

Initial AccessTA0001

Valid Accounts T1078 Medium also Persistence, Privilege Escalation, Stealth
AI mapping from the description · how it is exploited

Local low-privilege account required for exploitation

Windows Kernel Information Disclosure Vulnerability
From the official description (NVD) Original (opens in a new tab) ↗

Detection

0 rules for this CVE · 56 general rules for its techniques

Rules for this CVE

0 that reference CVE-2021-31955 directly.

CVE-specific rules are not available in this build. Search SigmaHQ ↗

General rules for this CVE’s techniques

These detect the technique in general, not this specific vulnerability.

Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.

What security researchers reported

Not named in any threat report yet

Also mentioned in 50 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

2 links, grouped by NVD tag (1 duplicate merged)
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