CVE-2021-3560 — polkit
HIGHCVE-2021-3560 is a high-severity (CVSS 7.8) CWE-863 vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2023-05-12) — treat it as actively exploited and patch now. A fix is available — see the affected versions and patch details below.
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2023-05-12. Federal agencies were required to remediate by 2023-06-02.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2021-3560.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-3560 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 395,249 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.
Description
It was found that polkit could be tricked into bypassing the credential checks for D-Bus requests, elevating the privileges of the requestor to the root user. This flaw could be used by an unprivileged local attacker to, for example, create a new local administrator. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Affected Products
ubuntu linuxcanonicaldebian linuxdebianpolkitpolkit_projectopenshift container platformredhatvirtualizationredhatvirtualization hostredhatResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Polkit 0.105-26 0.117-2 - Local Privilege Escalation
by J Smith · Jun 15, 2021
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2021-3560, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update as soon as possible.Source: Red Hat security advisory for CVE-2021-3560 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Enterprise Linux 8 | polkit-0:0.115-11.el8_4.1 | RHSA-2021:2238 |
| Red Hat Enterprise Linux 8.1 Extended Update Support | polkit-0:0.115-9.el8_1.1 | RHSA-2021:2236 |
| Red Hat Enterprise Linux 8.2 Extended Update Support | polkit-0:0.115-11.el8_2.1 | RHSA-2021:2237 |
| Red Hat OpenShift Container Platform 4.7 | cri-o-0:1.20.3-6.rhaos4.7.git0d0f863.el7 | RHSA-2021:2555 |
| Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 | redhat-virtualization-host-0:4.4.6-20210615.0.el8_4 | RHSA-2021:2522 |
Frequently Asked Questions
Is CVE-2021-3560 in your dependencies?
Find it across , including transitive dependencies.