Assessment
Why it matters
CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 94.9%; technical severity is CVSS 7.8.
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.
Who should care
- Teams operating Ubuntu Linux, Http Server, Zfs Storage Appliance Kit +27 more
- Vulnerability and exposure management teams
- Security operations teams monitoring exploitation activity
Response plan
What I would do
- Confirm whether Ubuntu Linux, Http Server, Zfs Storage Appliance Kit +27 more is present in the environment.
- Identify affected versions and establish whether vulnerable services are exposed or reachable.
- Apply updates per vendor instructions.
- Review relevant security telemetry for evidence of attempted or successful exploitation.
- Document the remediation decision and track it to verified completion.
Vendor remediation
Patch and remediation links
Use the vendor source below to confirm the correct fixed version, package or mitigation for your affected product.
Technical details
- CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CWE
- CWE-787
- Affected versions
- Canonical Ubuntu Linux (Version: 21.10); Oracle Http Server (Version: 12.2.1.4.0); Oracle Zfs Storage Appliance Kit (Version: 8.8); Polkit Project Polkit (End Excluding: 121); Red Hat Polkit; Redhat Enterprise Linux (Version: 8.0); Redhat Enterprise Linux Desktop (Version: 7.0); Redhat Enterprise Linux Eus (Version: 8.2)
- Published
- 28 January 2022
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
Signal timeline
- CVE published
- Added to CISA KEV
- Latest EPSS score: 94.9%
- Signal calculated at 85
External references
- Government advisory from www.cisa.gov
- Exploit information from www.vicarius.io
- Exploit information from packetstormsecurity.com
- Third-party advisory from packetstormsecurity.com
- Vendor advisory from access.redhat.com
- Third-party advisory from cert-portal.siemens.com
- Mitigation guidance from www.qualys.com
- Exploit information from www.secpod.com
- Third-party advisory from www.starwindsoftware.com
- Third-party advisory from www.suse.com