SB2021011821 - Privilege escalation in Flatpak
Published: January 18, 2021
Security Bulletin ID
SB2021011821
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) Code Injection (CVE-ID: CVE-2021-21261)
The vulnerability allows a local application to elevate privileges on the system.
The vulnerability exists due to improper input validation when processing environment variables, passed from a sandboxed process to a non-sandboxed process on the host system, and in particular to the `flatpak run` command that is used to launch the new sandbox instance. A malicious or compromised Flatpak app can set environment variables that are trusted by the `flatpak run` command, and use them to execute arbitrary code that is not in a sandbox.
Remediation
Install update from vendor's website.
References
- https://github.com/flatpak/flatpak/commit/57416f380600d9754df12baf5b227144ff1bb54d
- https://github.com/flatpak/flatpak/commit/6a11007021658518c088ba0cc5e4da27962a940a
- https://github.com/flatpak/flatpak/commit/dcd24941c7087c5f7e8033abe50b178ac02a34af
- https://github.com/flatpak/flatpak/commit/fb1eaefbceeb73f02eb1bc85865d74a414faf8b8
- https://github.com/flatpak/flatpak/releases/tag/1.8.5
- https://github.com/flatpak/flatpak/security/advisories/GHSA-4ppf-fxf6-vxg2
- https://www.debian.org/security/2021/dsa-4830