CVE-2021-4034Red Hat Polkit Out-of-Bounds Read and Write Vulnerability
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.
Overview
Severity
| Score | Severity | Version | Vector String |
|---|---|---|---|
| 7.8 | HIGH | 3.1NVD | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 7.2 | HIGH | 2.0NVD | AV:L/AC:L/Au:N/C:C/I:C/A:C |
CISA required action
⚡ Known exploited · remediation due Jul 18, 2022
Apply updates per vendor instructions.
Details
- CVE ID
- CVE-2021-4034
- Status
- Analyzed
- Assigner (CNA)
- redhat
- Published
- Jan 28, 2022
- Last modified
- 2026-08-15 04:17 UTC
Affected Products
As published by the CNA in the CVE record.
polkit1 version range
- all
References
- packetstormsecurity.com http://packetstormsecurity.com/files/166196/Polkit-pkexec-Local-Privilege-Escalation.html
- packetstormsecurity.com http://packetstormsecurity.com/files/166200/Polkit-pkexec-Privilege-Escalation.html
- access.redhat.com https://access.redhat.com/security/vulnerabilities/RHSB-2022-001
- bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=2025869
- cert-portal.siemens.com https://cert-portal.siemens.com/productcert/pdf/ssa-330556.pdf
- gitlab.freedesktop.org https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683
- oracle.com https://www.oracle.com/security-alerts/cpuapr2022.html
- qualys.com https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt
- secpod.com https://www.secpod.com/blog/local-privilege-escalation-vulnerability-in-major-linux-distributions-cve-2021-4034/
- starwindsoftware.com https://www.starwindsoftware.com/security/sw-20220818-0001/
- suse.com https://www.suse.com/support/kb/doc/?id=000020564
- vicarius.io https://www.vicarius.io/vsociety/posts/pwnkit-pkexec-lpe-cve-2021-4034
- cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-4034