CVE-2021-4034: Red Hat Polkit Out-of-Bounds Read and Write Vulnerability
Affects Red Hat PolkitSource CISA KEV
Exploited in the wild · used in ransomware campaigns · KEV due 18 Jul 2022 · public exploit available (Metasploit, Exploit-DB) · 94% EPSS : apply the vendor's fix or mitigations to Red Hat Polkit now.
Data as of 10/24/2026, 22:15:59 UTC
- Exploitation
Actively exploited – in CISA KEV since 06/27/2022
- KEV deadline
- 07/18/2022 US federal agencies must patch by this date; a sensible deadline for everyone else.
- Ransomware
- Used in ransomware campaigns
- EPSS
- 94.9% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Public exploits
- 1 Metasploit module, 1 Exploit-DB entryPublic attack or detection tooling exists; see Public exploits below.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HWhat to do
CISA required action
Apply updates per vendor instructions.
Public exploits and detection
Metasploit modules
Public tooling indexed from Metasploit Framework, Exploit-DB and ProjectDiscovery nuclei-templates. Its existence raises the odds of exploitation; it does not confirm attacks.
Description
The Red Hat polkit pkexec utility contains an out-of-bounds read and write vulnerability that allows for privilege escalation with administrative rights.
Weaknesses
- CWE-787Out-of-bounds Write (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #5
The product writes data past the end, or before the beginning, of the intended buffer.