| Name | CVE-2021-26910 |
| Description | 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. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more) |
| References | DLA-2554-1, DSA-4849-1 |
| NVD severity | medium |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| firejail (PTS) | stretch | 0.9.44.8-2 | vulnerable |
| stretch (security) | 0.9.44.8-2+deb9u2 | fixed | |
| buster | 0.9.58.2-2+deb10u1 | vulnerable | |
| buster (security) | 0.9.58.2-2+deb10u2 | fixed | |
| bullseye, sid | 0.9.64.4-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| firejail | source | stretch | 0.9.44.8-2+deb9u2 | DLA-2554-1 | ||
| firejail | source | buster | 0.9.58.2-2+deb10u2 | DSA-4849-1 | ||
| firejail | source | (unstable) | 0.9.64.4-1 |
https://www.openwall.com/lists/oss-security/2021/02/08/5
Fix (disabled overlayfs): https://github.com/netblue30/firejail/commit/97d8a03cad19501f017587cc4e47d8418273834b
https://unparalleled.eu/publications/2021/advisory-unpar-2021-0.txt
https://unparalleled.eu/blog/2021/20210208-rigged-race-against-firejail-for-local-root/