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CVE-2021-31956 KEVPublic exploit High · 7.8 EPSS 22.3%

Microsoft Windows NTFS Privilege Escalation Vulnerability

Microsoft · Windows

Summary

The vulnerability is an elevation of privilege flaw in the NTFS file system component of Microsoft Windows, involving integer underflow and out-of-bounds write weaknesses. An attacker with local access and low-privilege credentials can exploit it without user interaction to gain higher privileges on the affected system.

Official description · NVD

Windows NTFS Elevation of Privilege Vulnerability

Breakdown
65.0 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
1/15

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 7 months after disclosure.

  1. First seen exploitedVulnCheck KEV evidence55 days before
  2. Disclosedday 0
  3. Added to CISA KEVEU database agrees+5 mo
  4. Public exploit codePoC-in-GitHub+7 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

Privilege EscalationTA0004

Exploitation for Privilege Escalation T1068 Medium
AI mapping from the description · how it is exploited

Local privilege escalation via NTFS driver flaw

Windows NTFS Elevation of Privilege Vulnerability
From the official description (NVD) Original (opens in a new tab) ↗

Detection

0 rules for this CVE · 31 general rules for its techniques

Rules for this CVE

0 that reference CVE-2021-31956 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

References

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