High severity · published Jan 28, 2022
CVE-2021-4034
Red Hat Polkit Out-of-Bounds Read and Write Vulnerability
RansomwareIn wildKEV
7.8
CVSS
94.9%
EPSS
Yes
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)94.9% · higher than 100% of CVEs
Exploited in the wildYes
CISA KEVListed Jun 27, 2022
Federal remediation dueJul 18, 2022
Ransomware campaign useKnown
Affected products
Which versions
PO
Polkit · Polkit Project
before 121 · source: vendor, NVD, KEV
CC
Command Center · Starwindsoftware
1.0 · source: NVD
EL
Enterprise Linux · Redhat
8.0 · source: NVD
EL
Enterprise Linux Desktop · Redhat
7.0 · source: NVD
EL
Enterprise Linux Eus · Redhat
8.2 · source: NVD
EL
Enterprise Linux For Ibm Z Systems · Redhat
7.0; 8.0 · source: NVD
EL
Enterprise Linux For Ibm Z Systems Eus · Redhat
8.2; 8.4 · source: NVD
EL
Enterprise Linux For Power Big Endian · Redhat
7.0 · source: NVD
EL
Enterprise Linux For Power Little Endian · Redhat
7.0; 8.0 · source: NVD
EL
Enterprise Linux For Power Little Endian Eus · Redhat
8.1; 8.2; 8.4 · source: NVD
EL
Enterprise Linux For Scientific Computing · Redhat
7.0 · source: NVD
EL
Enterprise Linux Server · Redhat
6.0; 7.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-4034
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-4034
CISA KEV catalogue
https://www.cisa.gov/known-exploited-vulnerabilities-catalog
access.redhat.com
https://access.redhat.com/security/vulnerabilities/RHSB-2022-001
www.qualys.com
https://www.qualys.com/2022/01/25/cve-2021-4034/pwnkit.txt
bugzilla.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2025869
gitlab.freedesktop.org
https://gitlab.freedesktop.org/polkit/polkit/-/commit/a2bf5c9c83b6ae46cbd5c779d3055bff81ded683
www.oracle.com
https://www.oracle.com/security-alerts/cpuapr2022.html
packetstormsecurity.com
http://packetstormsecurity.com/files/166196/Polkit-pkexec-Local-Privilege-Escalation.html
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