Race condition in firejail - CVE-2021-26910
Published: February 14, 2021
Vulnerability identifier: #VU50675
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2021-26910
CWE-ID: CWE-367
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: firejail.wordpress.com
Affected software:
firejail
firejail
Detailed vulnerability description
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.
How to mitigate CVE-2021-26910
Install updates from vendor's website.
Sources
- 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