CVE-2021-3560
CVE-2021-3560 is a security flaw in Red Hat Polkit. Someone who already has a foothold can use Red Hat Polkit to take full control of the machine. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 12 May 2023.[1]
Red Hat Polkit is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Red Hat has published a fix or advice.
Description
CISA calls it an incorrect authorization in Red Hat Polkit. In its words: “Red Hat Polkit contains an incorrect authorization vulnerability through the bypassing of credential checks for D-Bus requests, allowing for privilege escalation.”[1]
The CVE record adds: “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.”[2]
The underlying weakness is incorrect authorization (CWE-863), in MITRE’s list of common software weaknesses.
It scores 7.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Red Hat’s advisory has them[3]. CISA names the product as Red Hat Polkit.
Most families won’t have Red Hat Polkit; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 12 May 2023, 450 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 2 Jun 2023 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 24%. That’s in the top 3% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Red Hat has published a fix or advice.[3] CISA’s required action: “Apply updates per vendor instructions.”[1]
- Check whether you use it.Red Hat Polkit is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 2 Jun 2023 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 24%.[4] |
See also
Other Red Hat Polkit flaws
- CVE-2021-4034: out-of-bounds read and write ·
Other Red Hat flaws
- CVE-2015-5287, Red Hat Automatic Bug Reporting Tool: privilege escalation ·
- CVE-2015-3246, Red Hat Libuser: race condition ·
- CVE-2018-14667, Red Hat JBoss RichFaces Framework: expression language injection ·
- CVE-2010-1428, Red Hat JBoss: information disclosure ·
- CVE-2010-0738, Red Hat JBoss: authentication bypass ·
Other incorrect authorization flaws
- CVE-2026-71362, Adobe Commerce and Magento: incorrect authorization ·
- CVE-2026-42016, JFrog Artifactory: incorrect authorization ·
- CVE-2025-54253, Adobe Experience Manager (AEM) Forms: experience manager forms code execution ·
- CVE-2025-55177, Meta Platforms WhatsApp: incorrect authorization ·
- CVE-2025-21480, Qualcomm Multiple Chipsets: incorrect authorization ·
Added the same day
- CVE-2023-25717, Ruckus Wireless products: multiple ruckus wireless products CSRF and RCE ·
- CVE-2016-8735, Apache Tomcat: remote code execution ·
- CVE-2016-3427, Oracle Java SE and JRockit: unspecified ·
- CVE-2015-5317, Jenkins User Interface (UI): user interface (UI) information disclosure ·
- CVE-2014-0196, Linux Kernel: race condition ·
Every Red Hat flaw on CISA’s list · Everything added in May 2023
References
- ^ Cybersecurity and Infrastructure Security Agency. “Red Hat Polkit Incorrect Authorization Vulnerability”. Known Exploited Vulnerabilities Catalog, added 12 May 2023.
- ^ National Institute of Standards and Technology. “CVE-2021-3560 Detail”. National Vulnerability Database, published 16 Feb 2022.
- ^ Red Hat. Advisories and fixes: bugzilla.redhat.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.237, percentile 97.8, 31 Oct 2026.
- CVE Program. “CVE-2021-3560”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.