Red Hat · Polkit
CVE-2021-4034
Red Hat Polkit Out-of-Bounds Read and Write Vulnerability
What it is
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.
CISA: The Red Hat polkit pkexec utility contains an out-of-bounds read and write vulnerability that allows for privilege escalation with administrative rights.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: July 18, 2022
- Added to the CISA list
- June 27, 2022
- Published
- January 28, 2022
- Severity
- High 7.8 CVSS 3.1
- Chance of attacks in the next 30 days (EPSS)
- 95% in the top 0.1% of all known vulnerabilities
- Weakness
- CWE-787
- More details
- NVD · CVE.org · CISA
All references (11)
- 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-2021-40…
More exploited flaws from Red Hat
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| May 12, 2023 | Incorrect Authorization | Polkit | High 7.8 | 24% |
| Aug 26, 2026 | Race Condition | Libuser | High 7.4 | 8.5% |
| Aug 26, 2026 | Privilege Escalation | Automatic Bug Reporting Tool | High 7.8 | 5.0% |
| Sep 28, 2023 | Expression Language Injection | JBoss RichFaces Framework | Critical 9.8 | 74% |
| May 25, 2022 | Authentication Bypass | JBoss | Low 3.7 | 74% |
| May 25, 2022 | Information Disclosure | JBoss | Medium 5.9 | 53% |
| Dec 10, 2021 | Linux JBoss Seam 2 Remote Code Execution | JBoss Seam 2 | High 8.8 | 83% |
| Dec 10, 2021 | Remote Code Execution | JBoss Application Server | Critical 9.8 | 91% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.