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CVE-2021-4034

Severity
HIGH
CVSS
7.8
EPSS
0.94921
Risk score
58.22
CISA KEV
Yes
PoC
Yes
Published
2022-01-28
Modified
2025-10-21
First seen
2026-08-07
Aliases
EUVD-2021-33934, GHSA-QGR2-XGQV-24X8
Products
Red Hat:Polkit, n/a:Polkit all, unix
Sources
packetstorm bd2236092be59388bfdefee2|CVE-2021-4034
cisa.gov CVE-2021-4034
euvd EUVD-2021-33934

Description

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.

References