CVE-2021-4034 | BDVDB-2026-0031 Detail
polkit
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.
Impact#
Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact high. Attack vector: local.
Weaknesses#
- CWE-787 Out-of-bounds Write
References#
- https://access.redhat.com/security/vulnerabilities/RHSB-2022-001
- https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt
- https://bugzilla.redhat.com/show_bug.cgi?id=2025869
- https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683
- https://www.oracle.com/security-alerts/cpuapr2022.html
- http://packetstormsecurity.com/files/166196/Polkit-pkexec-Local-Privilege-Escalation.html
- http://packetstormsecurity.com/files/166200/Polkit-pkexec-Privilege-Escalation.html
- https://www.suse.com/support/kb/doc/?id=000020564
- https://cert-portal.siemens.com/productcert/pdf/ssa-330556.pdf
- https://www.starwindsoftware.com/security/sw-20220818-0001/
- https://www.secpod.com/blog/local-privilege-escalation-vulnerability-in-major-linux-distributions-cve-2021-4034/
- 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
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.