CVEs-PoC/2021/CVE-2021-26910.md

### [CVE-2021-26910](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-26910)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### 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.

### POC

#### Reference
- 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://unparalleled.eu/publications/2021/advisory-unpar-2021-0.txt

#### Github
- https://github.com/netblue30/firejail
- https://github.com/orgTestCodacy11KRepos110MB/repo-1121-firejail
- https://github.com/sailfishos-mirror/firejail