CVE-2021-4034

HIGHNVD 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
7.8
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 95%CVSS: 7.8Exploit: NoneExposed: 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
99.9%
KEV
⚠ Exploited

Published

January 28, 2022

Last Modified

November 6, 2025

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
ubuntulibpolkit-gobject-1-0 (0.105-31ubuntu0.1) @ impish2026-07-22ubuntu
ubuntupolicykit-1-doc (0.105-14.1ubuntu0.5+esm1) @ xenial2026-07-22ubuntu
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-0:0.112-12.el7_3.12022-01-25redhat
redhatpolkit-0:0.112-12.el7_4.22022-01-25redhat
redhatpolkit-0:0.112-18.el7_6.32022-01-25redhat
redhatpolkit-0:0.112-22.el7_7.22022-01-25redhat
redhatpolkit-0:0.115-11.el8_2.22022-01-25redhat
redhatpolkit-0:0.115-11.el8_4.22022-01-25redhat
redhatpolkit-0:0.112-26.el7_9.12022-01-25redhat
redhatpolkit-0:0.96-11.el6_10.22022-01-25redhat
redhatpolkit-0:0.115-13.el8_5.12022-01-25redhat
redhatpolkit-0:0.115-9.el8_1.22022-01-25redhat

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.

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 62× in last 7d / 340× 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 663 total refreshes for this CVE.

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

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 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 ↗
  • 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 ↗
  • GitHub PoCY3A/CVE-2021-4034
    First seen Jan 26, 2022
    Open source ↗
  • GitHub PoCly4k/PwnKit
    First seen Jan 26, 2022

    Self-contained exploit for CVE-2021-4034 - Pkexec Local Privilege Escalation

    Open source ↗
  • GitHub PoCarthepsy/CVE-2021-4034
    First seen Jan 26, 2022

    PoC for PwnKit: Local Privilege Escalation Vulnerability in polkit’s pkexec (CVE-2021-4034)

    Open source ↗
  • GitHub PoCdadvlingd/CVE-2021-4034
    First seen Jan 26, 2022
    Open source ↗

Frequently asked(6)

What is CVE-2021-4034?
CVE-2021-4034 is a high 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 November 6, 2025. 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

Explore the affected products and dependency analysis for CVE-2021-4034

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