CVE-2021-4034

CRITICALNVD 7.89.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2022-06-27), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 7.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 5 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 95%CVSS: 7.8Exploit: cisa kev · ssvc active · kev ransomware · Metasploit · epss top5pct · epss high · public exploitExposed: 0

A fix is available — apply it.

A local privilege escalation vulnerability was found on polkit's pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn't handle the calling parameters count correctly and ends trying to execute environment variables as commands. An attacker can leverage this by crafting environment variables in such a way it'll induce pkexec to execute arbitrary code. When successfully executed the attack can cause a local privilege escalation given unprivileged users administrative rights on the target machine.

CVSS v3
7.8
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
95%
EPSS %ILE
100%
KEV
⚠ Exploited

Published

January 28, 2022

Last Modified

August 15, 2026

Advisory Details (8)

Auto-updated Jun 4, 2026
Patch available. Sources: redhat.
generic

CVE-2021-4034 PolicyKit privilege escalation vulnerability in StarWind products

https://www.starwindsoftware.com/security/sw-20220818-0001/
generic

PwnKit Linux vulnerability Jan-2022: Local Privilege Escalation Vulner | SecPod

https://www.secpod.com/blog/local-privilege-escalation-vulnerability-in-major-linux-distributions-cve-2021-4034/
generic
https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt
generic

pkexec: local privilege escalation (CVE-2021-4034) (a2bf5c9c) · Commits · polkit / polkit · GitLab

https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683
redhat Patch Available

2025869 – (CVE-2021-4034) CVE-2021-4034 polkit: Local privilege escalation in pkexec due to incorrect handling of argument vector

Affected: Red Hat Enterprise Linux 8.2 Extended Update Support

https://bugzilla.redhat.com/show_bug.cgi?id=2025869
redhat Patch Available

RHSB-2022-001 Polkit Privilege Escalation - (CVE-2021-4034) | Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 6

https://access.redhat.com/security/vulnerabilities/RHSB-2022-001
generic

Packet Storm

http://packetstormsecurity.com/files/166200/Polkit-pkexec-Privilege-Escalation.html
generic

Packet Storm

http://packetstormsecurity.com/files/166196/Polkit-pkexec-Local-Privilege-Escalation.html

Vendor Advisories for CVE-2021-4034(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(14)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntupolicykit-1-doc (0.105-14.1ubuntu0.5+esm1) @ xenial2026-09-20ubuntu
ubuntulibpolkit-gobject-1-0 (0.105-31ubuntu0.1) @ impish2026-09-20ubuntu
redhatredhat-virtualization-host-0:4.4.10-202202081536_8.52022-02-15redhat
redhatredhat-virtualization-host-0:4.3.21-20220126.0.el7_92022-02-07redhat
redhatpolkit-0:0.112-18.el7_6.32022-01-25redhat
redhatpolkit-0:0.112-22.el7_7.22022-01-25redhat
redhatpolkit-0:0.115-13.el8_5.12022-01-25redhat
redhatpolkit-0:0.115-9.el8_1.22022-01-25redhat
redhatpolkit-0:0.115-11.el8_4.22022-01-25redhat
redhatpolkit-0:0.112-12.el7_3.12022-01-25redhat
redhatpolkit-0:0.115-11.el8_2.22022-01-25redhat
redhatpolkit-0:0.112-26.el7_9.12022-01-25redhat
redhatpolkit-0:0.96-11.el6_10.22022-01-25redhat
redhatpolkit-0:0.112-12.el7_4.22022-01-25redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(6 across 6 ecosystems)
Debian:10(1)
PackageVulnerable rangeFixed inDependents
policykit-10.105-250.105-25+deb10u1—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
policykit-10.105-310.105-31+deb11u1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
policykit-1—0.105-31.1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
policykit-1—0.105-31.1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
policykit-1—0.105-31.1—
Debian:9(1)
PackageVulnerable rangeFixed inDependents
policykit-10.105-18, 0.105-18+deb9u10.105-18+deb9u2—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(14)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 84× in last 7d / 373× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 1,361 total refreshes for this CVE.

  1. 2026-09-20 16:24 UTCVendor advisory
  2. 2026-09-20 16:24 UTCGHSA enrichment
  3. 2026-09-20 12:08 UTCVendor advisory
  4. 2026-09-20 12:08 UTCGHSA enrichment
  5. 2026-09-20 07:51 UTCVendor advisory
  6. 2026-09-20 07:51 UTCGHSA enrichment
  7. 2026-09-20 03:32 UTCVendor advisory
  8. 2026-09-20 03:32 UTCGHSA enrichment
  9. 2026-09-19 23:17 UTCVendor advisory
  10. 2026-09-19 23:17 UTCGHSA enrichment
  11. 2026-09-19 19:01 UTCVendor advisory
  12. 2026-09-19 19:01 UTCGHSA enrichment
  13. 2026-09-19 14:45 UTCVendor advisory
  14. 2026-09-19 14:45 UTCGHSA enrichment
  15. 2026-09-19 10:29 UTCVendor advisory
  16. 2026-09-19 10:29 UTCGHSA enrichment
  17. 2026-09-19 06:12 UTCVendor advisory
  18. 2026-09-19 06:12 UTCGHSA enrichment
  19. 2026-09-19 01:55 UTCVendor advisory
  20. 2026-09-19 01:55 UTCGHSA enrichment
  21. 2026-09-18 21:39 UTCVendor advisory
  22. 2026-09-18 21:39 UTCGHSA enrichment
  23. 2026-09-18 19:20 UTCCISA KEV update
  24. 2026-09-18 17:23 UTCVendor advisory
  25. 2026-09-18 17:23 UTCGHSA enrichment
Show 75 more
  1. 2026-09-18 14:15 UTCCISA KEV update
  2. 2026-09-18 13:07 UTCVendor advisory
  3. 2026-09-18 13:07 UTCGHSA enrichment
  4. 2026-09-18 08:51 UTCVendor advisory
  5. 2026-09-18 08:51 UTCGHSA enrichment
  6. 2026-09-18 04:35 UTCVendor advisory
  7. 2026-09-18 04:35 UTCGHSA enrichment
  8. 2026-09-18 00:19 UTCVendor advisory
  9. 2026-09-18 00:19 UTCGHSA enrichment
  10. 2026-09-17 20:03 UTCEG score recompute
  11. 2026-09-17 20:03 UTCVendor advisory
  12. 2026-09-17 20:03 UTCGHSA enrichment
  13. 2026-09-17 19:23 UTCEPSS rescore
  14. 2026-09-17 15:47 UTCVendor advisory
  15. 2026-09-17 15:47 UTCGHSA enrichment
  16. 2026-09-17 11:31 UTCVendor advisory
  17. 2026-09-17 11:31 UTCGHSA enrichment
  18. 2026-09-17 07:15 UTCVendor advisory
  19. 2026-09-17 07:14 UTCGHSA enrichment
  20. 2026-09-17 02:56 UTCVendor advisory
  21. 2026-09-17 02:56 UTCGHSA enrichment
  22. 2026-09-16 22:41 UTCVendor advisory
  23. 2026-09-16 22:41 UTCGHSA enrichment
  24. 2026-09-16 18:25 UTCVendor advisory
  25. 2026-09-16 18:24 UTCGHSA enrichment
  26. 2026-09-16 14:10 UTCCISA KEV update
  27. 2026-09-16 14:09 UTCVendor advisory
  28. 2026-09-16 14:09 UTCGHSA enrichment
  29. 2026-09-16 09:53 UTCVendor advisory
  30. 2026-09-16 09:53 UTCGHSA enrichment
  31. 2026-09-16 05:36 UTCVendor advisory
  32. 2026-09-16 05:36 UTCGHSA enrichment
  33. 2026-09-16 01:21 UTCVendor advisory
  34. 2026-09-16 01:21 UTCGHSA enrichment
  35. 2026-09-15 21:03 UTCVendor advisory
  36. 2026-09-15 21:03 UTCGHSA enrichment
  37. 2026-09-15 16:48 UTCVendor advisory
  38. 2026-09-15 16:47 UTCGHSA enrichment
  39. 2026-09-15 12:32 UTCVendor advisory
  40. 2026-09-15 12:31 UTCGHSA enrichment
  41. 2026-09-15 08:15 UTCVendor advisory
  42. 2026-09-15 08:15 UTCGHSA enrichment
  43. 2026-09-15 03:59 UTCVendor advisory
  44. 2026-09-15 03:59 UTCGHSA enrichment
  45. 2026-09-14 23:42 UTCVendor advisory
  46. 2026-09-14 23:42 UTCGHSA enrichment
  47. 2026-09-14 19:26 UTCVendor advisory
  48. 2026-09-14 19:26 UTCGHSA enrichment
  49. 2026-09-14 19:24 UTCCISA KEV update
  50. 2026-09-14 15:10 UTCVendor advisory
  51. 2026-09-14 15:10 UTCGHSA enrichment
  52. 2026-09-14 10:54 UTCVendor advisory
  53. 2026-09-14 10:54 UTCGHSA enrichment
  54. 2026-09-14 06:38 UTCVendor advisory
  55. 2026-09-14 06:38 UTCGHSA enrichment
  56. 2026-09-14 02:22 UTCVendor advisory
  57. 2026-09-14 02:22 UTCGHSA enrichment
  58. 2026-09-13 22:07 UTCVendor advisory
  59. 2026-09-13 22:07 UTCGHSA enrichment
  60. 2026-09-13 17:51 UTCVendor advisory
  61. 2026-09-13 17:51 UTCGHSA enrichment
  62. 2026-09-13 13:35 UTCVendor advisory
  63. 2026-09-13 13:35 UTCGHSA enrichment
  64. 2026-09-13 09:19 UTCVendor advisory
  65. 2026-09-13 09:19 UTCGHSA enrichment
  66. 2026-09-13 05:03 UTCVendor advisory
  67. 2026-09-13 05:03 UTCGHSA enrichment
  68. 2026-09-13 00:47 UTCVendor advisory
  69. 2026-09-13 00:47 UTCGHSA enrichment
  70. 2026-09-12 20:31 UTCVendor advisory
  71. 2026-09-12 20:31 UTCGHSA enrichment
  72. 2026-09-12 16:15 UTCEG score recompute
  73. 2026-09-12 16:15 UTCVendor advisory
  74. 2026-09-12 16:15 UTCGHSA enrichment
  75. 2026-09-12 14:57 UTCEPSS rescore

Publicly available exploits

(10 references)

Working exploit code is in the public domain (9 GitHub PoCs) (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCwechicken456/CVE-2021-4034-CTF-writeup
    First seen Feb 4, 2024
    Open source ↗
  • GitHub PoCPixailz/CVE-2021-4034
    First seen Oct 10, 2022

    polkit priv esc: pkexec out of boundary exploit

    Open source ↗
  • GitHub PoCwudicainiao/cve-2021-4034
    First seen May 21, 2022

    CVE-2021-4034 for single commcand

    Open source ↗
  • GitHub PoCrvizx/CVE-2021-4034
    First seen Feb 4, 2022

    PoC for PwnKit: Local Privilege Escalation Vulnerability in polkit’s pkexec in Python

    Open source ↗
  • GitHub PoCrvzsec/CVE-2021-4034
    First seen Feb 4, 2022

    PoC for PwnKit: Local Privilege Escalation Vulnerability in polkit’s pkexec in Python

    Open source ↗
  • GitHub PoCRvn0xsy/CVE-2021-4034
    First seen Jan 28, 2022

    CVE-2021-4034 Add Root User - Pkexec Local Privilege Escalation

    Open source ↗
  • GitHub PoCEstamelGG/CVE-2021-4034-NoGCC
    First seen Jan 28, 2022

    CVE-2021-4034简单优化，以应对没有安装gcc和make的目标环境

    Open source ↗
  • Exploit-DBEDB-50689
    First seen Jan 27, 2022

    PolicyKit-1 0.105-31 - Privilege Escalation

    Open source ↗
  • GitHub PoCPwnFunction/CVE-2021-4034
    First seen Jan 27, 2022

    Proof of concept for pwnkit vulnerability

    Open source ↗
  • GitHub PoCtahaafarooq/poppy
    First seen Jan 27, 2022

    CVE-2021-4034 PoC , polkit < 0.131

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(6)

What is CVE-2021-4034?
CVE-2021-4034 is a critical vulnerability published on January 28, 2022. A local privilege escalation vulnerability was found on polkit's pkexec utility. The pkexec application is a setuid tool designed to allow unprivileged users to run commands as privileged users according predefined policies. The current version of pkexec doesn't handle the calling parameters count…
When was CVE-2021-4034 disclosed?
CVE-2021-4034 was first published in the National Vulnerability Database on January 28, 2022, with the most recent update on August 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-4034 actively exploited?
Yes. CISA added CVE-2021-4034 to the Known Exploited Vulnerabilities catalog on June 27, 2022, affecting Red Hat Polkit. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-4034?
CVE-2021-4034 has a CVSS v3 base score of 7.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2021-4034?
CVE-2021-4034 affects Red Hat Polkit. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2021-4034?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-4034, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-4034

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