Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2021-4034

7.8 · HIGHActively Exploited

A local privilege escalation vulnerability was found on polkit's pkexec utility.

Published Jan 28, 2022CWE-787EPSS 94.92%

Overview

CVE-2021-4034 is a high-severity vulnerability. It was published on January 28, 2022 and has a CVSS 3.1 base score of 7.8 (HIGH). This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild.

This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.

Technical 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.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References

Refpacketstormsecurity.com/files/166196/Polkit-pkexec-Local-Privilege-Escalation.htmlRefpacketstormsecurity.com/files/166200/Polkit-pkexec-Privilege-Escalation.htmlRefaccess.redhat.com/security/vulnerabilities/RHSB-2022-001Refbugzilla.redhat.com/show_bug.cgi?id=2025869Refcert-portal.siemens.com/productcert/pdf/ssa-330556.pdfRefgitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683Refwww.oracle.com/security-alerts/cpuapr2022.htmlRefwww.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txtRefwww.secpod.com/blog/local-privilege-escalation-vulnerability-in-major-linux-distributions-cve-2021-4034/Refwww.starwindsoftware.com/security/sw-20220818-0001/

How CyberStrike helps

Frequently asked questions

What is CVE-2021-4034?

CVE-2021-4034 is a high-severity vulnerability. It was published on January 28, 2022 and has a CVSS 3.1 base score of 7.8 (HIGH). This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation in the wild.

How severe is CVE-2021-4034?

This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.

How do I fix or remediate CVE-2021-4034?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2021-4034?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2021-4034 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related HIGH CVEs from 2021

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999