June 27, 2022 · Applied Cybernetics Group
CVE-2021-4034 — Red Hat Polkit
known ransomware use
Red Hat Polkit Out-of-Bounds Read and Write Vulnerability
- Added to KEV
2022-06-27- Federal due date
2022-07-18- Vendor
- Red Hat
- Product
- Polkit
- EPSS
- 99.9th percentile (score 0.949, as of
2026-09-16) - NVD CVSS v3.1
- 7.8 (HIGH)
- Ransomware use
- Known
- ATT&CK
- T1068 · signal rollup
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2021-4034
CISA short description
The Red Hat polkit pkexec utility contains an out-of-bounds read and write vulnerability that allows for privilege escalation with administrative rights.
Required action
Apply updates per vendor instructions.
NVD 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.