It was found that polkit could be tricked into bypassing the credential checks for D-Bus requests, elevating the privileges of the requestor
Affects polkit from 0.113 onward when a calling process disconnects from dbus-daemon at the wrong moment and the caller skips an error check. Fixed in polkit 0.119.
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Listed in CISA KEV
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Actively exploited
- Fix
- Fixed in 0.119
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Polkit, a system component that manages authorization for privileged actions on Linux systems, is affected by this flaw. A local user with no special privileges could exploit it to gain root access, allowing them to create new administrator accounts and compromise the confidentiality, integrity, and availability of the system.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original 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.
Timeline
- CVE published
- Added to CISA KEV
CISA has evidence of exploitation in the wild
- CISA remediation deadline
Due date for US federal agencies to patch
- Record last updated
- EPSS reached 10%
FIRST estimates at least a 10% chance of exploitation in the next 30 days
Affected versions
- n/a polkit
polkit 0.119
References 4
bugzilla.redhat.com
Questions about CVE-2021-3560
What does this mean?
A local process can disconnect from the D-Bus message daemon at a precise moment, which tricks polkit into skipping its credential check on the request. The request then runs with root privileges, so an unprivileged local user can perform actions such as installing packages or creating new administrators.Source: bugzilla.redhat.com, github.blog
Am I affected, and how do I check?
The flaw is in polkit starting from version 0.113, and the advisory names RHEL 8 and Fedora 21 or later among vulnerable distributions. The bug needs calling code that does not check whether polkit_system_bus_name_get_creds_sync set an error, so check your installed polkit version with pkaction --version.Source: bugzilla.redhat.com, github.blog
What should I do about it?
Upgrade polkit to version 0.119 or later, which contains the fix. Install the update from your distribution's package manager.Source: bugzilla.redhat.com, github.blog
Is it being exploited?
Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2023-05-12, which means it has evidence of attacks. No public exploit code is tracked.Source: cisa.gov, cve.now feed data