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CVE-2021-4034

Exploitation: active CVSS 7.8 HIGH Ransomware: known use

CVSS base score: 7.8 (High) CISA · v3.1

Score assigned by CISA's Vulnrichment program; the vendor's CVE record did not include one.

Red Hat Polkit Out-of-Bounds Read and Write Vulnerability

Vendor: Red Hat   Product: Polkit

Description

The Red Hat polkit pkexec utility contains an out-of-bounds read and write vulnerability that allows for privilege escalation with administrative rights.

Lifecycle Timeline

Each milestone comes from a different source, so gaps between them are gaps in what those sources publish, not evidence that nothing happened. EPSS history for this CVE holds 255 points from 2022-01-29, tracked daily from 2026-09-09; earlier points are weekly, which dates a spike to within a week. Peak probability 94.9% on 2026-06-20.

Published Applicability

Red Hat CSAF/VEX 0 affected · 251 fixed · 20 not affected
OSV.dev (incl. GHSA) 2 affected · 2 fixed · 0 not affected
CVE List v5 (CNA container) 1 affected · 0 fixed · 0 not affected

Check whether a specific version is affected →

What each source publishes about which product versions carry this vulnerability, kept as written rather than merged. Absence here means no source has published applicability data, not that nothing is affected.

Research & News Coverage

No mentions found in monitored research blogs or news feeds.

Detection & Exploitation

Network IDS/IPS
none published
Host / SIEM

Coverage across public collections only: Nuclei and OpenVAS NVT (scan); Snort and Suricata ET Open (network); Sigma and YARA (host/SIEM); Metasploit, Exploit-DB and public GitHub repositories (exploit). Absence here means nothing public was found, not that detection is impossible.
GitHub PoC repositories are collected automatically by PoC-in-GitHub (CC0) and are not vetted: some are fakes and some are malware. Treat them as evidence that code was published, not as code to run.
OpenVAS coverage derives from the Greenbone Community Feed, made available under the Open Database License (ODbL) v1.0; its individual Vulnerability Tests are licensed GNU GPL v2.

Distribution Status

Debian · policykit-1 bookworm 0.105-31.1 trixie 0.105-31.1 forky 0.105-31.1 sid 0.105-31.1 scope: local

Where the distribution has shipped a fix, and in which version. Green means the release has resolved it, amber that it is still open. Data from the Debian Security Tracker, used under Debian's MIT / GPLv2+ terms. Debian is upstream of several other distributions, so a fix here often precedes theirs.

CISA Assessment (Vulnrichment / SSVC)

active
no
total
7.8 HIGH
—
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-787 — (CWE-787|CWE-125)
2024-10-29

D3FEND Countermeasures

Defensive techniques inferred by MITRE D3FEND from the underlying weakness (CWE-787) — general hardening and detection guidance for this weakness class, not a vendor patch for this specific CVE.

KEV Catalog Status

2022-06-27
2022-07-18
Known

Listed By

SourceDateRecord
CISA KEV 2022-06-27 source record →
CISA Vulnrichment 2024-10-29 source record →

Referenced in Advisories

DateAdvisoryIssuer
2024-11-12 2023 Top Routinely Exploited Vulnerabilities CISA
2024-09-05 Russian Military Cyber Actors Target US and Global Critical Infrastructure NSA
2024-09-05 Russian Military Cyber Actors Target U.S. and Global Critical Infrastructure NSA

Weaponization Timeline — Offensive & Testing Tools

DateToolEvidence qualityReference
2023-07-20 Empire Indirect — framework reference Release: Release: v5.5.3

Evidence tiers are explained on the About page — a merged Metasploit module is far stronger evidence than a distro package mention.

External References