CVE-2021-4034

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.

• CWE-787
• CWE-125
• CWE-787

• http://packetstormsecurity.com/files/166196/Polkit-pkexec-Local-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
• http://packetstormsecurity.com/files/166200/Polkit-pkexec-Privilege-Escalation.htmlThird Party Advisory, VDB Entry
• https://access.redhat.com/security/vulnerabilities/RHSB-2022-001Mitigation, Vendor Advisory
• https://bugzilla.redhat.com/show_bug.cgi?id=2025869Issue Tracking, Patch
• https://cert-portal.siemens.com/productcert/pdf/ssa-330556.pdfThird Party Advisory
• https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683Patch
• https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
• https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txtExploit, Mitigation, Third Party Advisory
• https://www.secpod.com/blog/local-privilege-escalation-vulnerability-in-major-linux-distributions-cve-2021-4034/Exploit, Third Party Advisory
• https://www.starwindsoftware.com/security/sw-20220818-0001/Third Party Advisory
• https://www.suse.com/support/kb/doc/?id=000020564Third Party Advisory
• http://packetstormsecurity.com/files/166196/Polkit-pkexec-Local-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
• http://packetstormsecurity.com/files/166200/Polkit-pkexec-Privilege-Escalation.htmlThird Party Advisory, VDB Entry
• https://access.redhat.com/security/vulnerabilities/RHSB-2022-001Mitigation, Vendor Advisory
• https://bugzilla.redhat.com/show_bug.cgi?id=2025869Issue Tracking, Patch
• https://cert-portal.siemens.com/productcert/pdf/ssa-330556.pdfThird Party Advisory
• https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683Patch
• https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
• https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txtExploit, Mitigation, Third Party Advisory
• https://www.secpod.com/blog/local-privilege-escalation-vulnerability-in-major-linux-distributions-cve-2021-4034/Exploit, Third Party Advisory
• https://www.starwindsoftware.com/security/sw-20220818-0001/Third Party Advisory
• https://www.suse.com/support/kb/doc/?id=000020564Third Party Advisory
• https://www.vicarius.io/vsociety/posts/pwnkit-pkexec-lpe-cve-2021-4034Exploit, Third Party Advisory
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-4034US Government Resource

Published

Jan 28, 2022

Last Modified

Jun 17, 2026

Status

Analyzed