CVE-2021-4034

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2022-06-27. Federal remediation due 2022-07-18.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

94.92% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 99.9% of scored records. A rank, not a probability.

NVD base score

7.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-08-15.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2022-01-28 00:00Z4 YR AGO

Last updated

2026-08-15 03:55Z20 DAYS AGO

Reserved

2021-11-29

Assigning CNA

redhat

Record state

PUBLISHED

Severity

High (CVSS 7.8)

CNA CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weaknesses

• CWE-787Out-of-bounds WriteBase

Data version

5.2

Document digest

323b8dd410e5d8114f03054670ec3ce49220e93dad3a5baf3cf0240c1e80365b

• access.redhat.comhttps://access.redhat.com/security/vulnerabilities/RHSB-2022-001
• www.qualys.comhttps://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt
• bugzilla.redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=2025869
• gitlab.freedesktop.orghttps://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuapr2022.html
• packetstormsecurity.comhttp://packetstormsecurity.com/files/166196/Polkit-pkexec-Local-Privilege-Escalation.html
• packetstormsecurity.comhttp://packetstormsecurity.com/files/166200/Polkit-pkexec-Privilege-Escalation.html
• www.suse.comhttps://www.suse.com/support/kb/doc/?id=000020564
• cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/pdf/ssa-330556.pdf
• www.starwindsoftware.comhttps://www.starwindsoftware.com/security/sw-20220818-0001/
• www.secpod.comhttps://www.secpod.com/blog/local-privilege-escalation-vulnerability-in-major-linux-distributions-cve-2021-4034/
• www.vicarius.iohttps://www.vicarius.io/vsociety/posts/pwnkit-pkexec-lpe-cve-2021-4034
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-4034government-resource