SB2021021403 - Privilege escalation in Firejail
Published: February 14, 2021
Security Bulletin ID
SB2021021403
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Race condition (CVE-ID: CVE-2021-26910)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a TOCTOU race condition between a stat operation and an OverlayFS mount operation in firejail. A local user can escalate privileges on the system.
Remediation
Install update from vendor's website.
References
- http://www.openwall.com/lists/oss-security/2021/02/09/1
- https://github.com/netblue30/firejail/commit/97d8a03cad19501f017587cc4e47d8418273834b
- https://github.com/netblue30/firejail/releases/tag/0.9.64.4
- https://lists.debian.org/debian-lts-announce/2021/02/msg00015.html
- https://unparalleled.eu/blog/2021/20210208-rigged-race-against-firejail-for-local-root/
- https://unparalleled.eu/publications/2021/advisory-unpar-2021-0.txt
- https://www.debian.org/security/2021/dsa-4849