CVE-2021-4034
HIGHCISA KEVEPSS 100th pctlDescription
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 Vector
Exploitability
Impact
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Very high risk: more likely to be exploited than 100% of all known CVEs.
Red Hat Polkit Out-of-Bounds Read and Write Vulnerability
The Red Hat polkit pkexec utility contains an out-of-bounds read and write vulnerability that allows for privilege escalation with administrative rights.
Apply updates per vendor instructions.
Remediation due: 2022-07-18
References
- http://packetstormsecurity.com/files/166196/Polkit-pkexec-Local-Privilege-Escalation.html
- http://packetstormsecurity.com/files/166200/Polkit-pkexec-Privilege-Escalation.html
- https://access.redhat.com/security/vulnerabilities/RHSB-2022-001
- https://bugzilla.redhat.com/show_bug.cgi?id=2025869
- https://cert-portal.siemens.com/productcert/pdf/ssa-330556.pdf
- https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt
- https://www.secpod.com/blog/local-privilege-escalation-vulnerability-in-major-linux-distributions-cve-2021-4034/
- https://www.starwindsoftware.com/security/sw-20220818-0001/
- https://www.suse.com/support/kb/doc/?id=000020564
- https://www.vicarius.io/vsociety/posts/pwnkit-pkexec-lpe-cve-2021-4034
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-4034
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-06.