Vulnerability details
CVE-2021-4034
Actively exploited
polkit
CVSS 3.1
7.8High
Official 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.
Related news
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.8High | 3.1 | CISA ADP / Vulnrichment (CISA-ADP) | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| — | polkit | all | CVEProject cvelistV5 (CNA) |
References and advisories
13- https://www.vicarius.io/vsociety/posts/pwnkit-pkexec-lpe-cve-2021-4034
- 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.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-4034 government-resource
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Details
- Published
- 2022-01-28
- Last updated
- 2026-08-15
- State
- Published
- Assigner (CNA)
- redhat
- Kolun priority
- 77 · High
CISA KEV catalog
- Date added
- 2022-06-27
- Due date
- 2022-07-18
- Used in ransomware
- Yes
Exploit prediction (EPSS)
94.92%
Probability of exploitation in 30 days
99.8%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- Active
- Technical impact
- Total
Weaknesses (CWE)
- CWE-787(CWE-787|CWE-125)