Vulnerability in Firejail Project
CVE-2021-26910
Firejail before 0.9.64.4 allows attackers to bypass intended access restrictions because there is a TOCTOU race condition between a stat operation and an OverlayFS mount operation.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (36.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Firejail Project
- Debian Linux — versions 9.0, 10.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/netblue30/firejail/commit/97d8a03cad19501f017587cc4e47d8418273834b (Patch, Third Party Advisory)
- unparalleled.eu/publications/2021/advisory-unpar-2021-0.txt (Exploit, Third Party Advisory)
- unparalleled.eu/blog/2021/20210208-rigged-race-against-firejail-for-local-root/ (Exploit, Third Party Advisory)
- github.com/netblue30/firejail/releases/tag/0.9.64.4 (Third Party Advisory, Release Notes)
- www.openwall.com/lists/oss-security/2021/02/09/1 (mailing-list, Exploit, Patch, Mailing List, Third Party Advisory)
- www.debian.org/security/2021/dsa-4849 (vendor-advisory, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2021/02/msg00015.html (mailing-list, Third Party Advisory)
- security.gentoo.org/glsa/202105-19 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-26910?
- CVE-2021-26910 is a high-severity vulnerability in Firejail Project, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 7.8/10. Published 2021-02-08.
- How severe is CVE-2021-26910?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2021-26910 known to be exploited?
- 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.