CVE-2021-3560 — Red Hat Polkit Incorrect Authorization Vulnerability
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Confirmed exploitation (CISA KEV)+35
- Public exploit/PoC (metasploit, exploitdb, github)+20
- EPSS 23.7% (30-day exploitation probability)+15
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — bugzilla.redhat.com (NIST National Vulnerability Database)
CISA required action CISA
Apply updates per vendor instructions.
US federal deadline: Jun 2, 2023 — passed 1231 day(s) ago
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Canonical Ubuntu Linux, Debian Debian Linux, Polkit Project Polkit…).
- Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
- Apply the fixed version or the patch documented under Remediation.
- EPSS ahead of 98% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (logic error), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Canonical | Ubuntu Linux | version 20.04 | Vulnerable | NIST National Vulnerability Database |
| Debian | Debian Linux | version 11.0 | Vulnerable | NIST National Vulnerability Database |
| Polkit Project | Polkit | < 0.119 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Openshift Container Platform | version 4.7 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Virtualization | version 4.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Virtualization Host | version 4.0 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.8 | CVSS 3.1 | High | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
| 7.2 | CVSS 2.0 | High | 3.9 | 10.0 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CWE-754 · Improper Check for Unusual or Exceptional Conditions
CISA KEV details CISA
CISA lists a CVE once it has evidence of exploitation against real targets.
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.
Public exploits, PoCs and detection templates
Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.
- Polkit D-Bus Authentication Bypass excellent Jun 3, 2021
- Polkit 0.105-26 0.117-2 - Local Privilege Escalation verified Jun 15, 2021
- secnigma/CVE-2021-3560-Polkit-Privilege-Esclation ★ 126 Jun 14, 2021
- Privilege escalation with polkit - CVE-2021-3560 ★ 125 Jun 19, 2021
- PolicyKit CVE-2021-3560 Exploit (Authentication Agent) ★ 116 Apr 29, 2022
- CVE-2021-3560 Local PrivEsc Exploit ★ 82 Jun 11, 2021
- a reliable C based exploit and writeup for CVE-2021-3560. ★ 40 Jun 12, 2021
- PolicyKit CVE-2021-3560 Exploitation (Authentication Agent) ★ 25 Apr 30, 2022
- AssassinUKG/Polkit-CVE-2021-3560 ★ 24 Jun 29, 2021
- Exploit for CVE-2021-3560 (Polkit) - Local Privilege Escalation ★ 12 May 2, 2022
- Polkit D-Bus Authentication Bypass Exploit ★ 9 Jul 30, 2021
- CVE-2021-3560 analysis ★ 9 Jan 31, 2022
Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.
EPSS over time FIRST
Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 23.71%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Hunt retroactively in logs from before May 12, 2023 (KEV listing): exploitation may have started earlier.
Timeline
What happened to this CVE, newest first.
- 2026
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · polkit project/polkit, debian/debian linux, canonical/ubuntu linux, redhat/virtualization, redhat/virtualization host, r
- CVSS changed · 7.8
- Source status changed · → Analyzed
- Added to CISA KEV (detected)
- Record created in this database
- 2023
- Added to CISA KEV catalog
- 2022
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 13, 2026 – Oct 13, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
8 on the record
- bugzilla.redhat.com/show_bug.cgi
- www.cisa.gov/known-exploited-vulnerabilities-catalog
- packetstormsecurity.com/files/172846/Facebook-Fizz-Denial-Of-Service.html
- github.blog/2021-06-10-privilege-escalation-polkit-root-on-linux-with-bug/
- github.blog/2021-06-10-privilege-escalation-polkit-root-on-linux-with-bug
- nvd.nist.gov/vuln/detail/CVE-2021-3560
- github.com/advisories/GHSA-7c49-j253-wq5r
- packetstormsecurity.com/files/172836/polkit-Authentication-Bypass.html
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-104046 Sssd: sssd: denial of service via incomplete identity provider authentication requests 9d
- Medium CVE-2026-104045 Sssd: sssd: denial of service via race condition in autofs responder 9d
- High CVE-2026-104048 Sssd: sssd: authorization bypass via cross-domain username collision in hbac evaluation 9d
- Medium CVE-2026-104047 Sssd: sssd: information disclosure via query injection in entra id lookups 9d
- Medium CVE-2026-90462 Sssd: sssd: fail-open in ldap ppolicy access check allows continued authorization 23d
- Medium CVE-2026-90995 Sssd: sssd: local denial of service due to null pointer dereference in pam responder Sep 14, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2021-3560 is "Red Hat Polkit Incorrect Authorization Vulnerability", rated High. It affects Ubuntu Linux (Canonical); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.8 describes technical severity. EPSS 23.71% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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