Ubuntu 26.10 backports sudo-rs privilege escalation fix
Ubuntu 26.10 receives the sudo-rs fix for a time-of-check vs time-of-use vulnerability in sudoedit that could allow local privilege escalation on systems with fine-grained sudoedit permissions.
Summary
Ubuntu has backported USN-8708-1 to Ubuntu 26.10 as USN-8708-2. The original advisory addressed a vulnerability in sudo-rs, the Rust rewrite of sudo, where sudoedit's handling of time-of-check vs time-of-use conditions could let a local attacker with sudoedit permissions write files to arbitrary directories and potentially escalate privileges. The vulnerable configuration—fine-grained sudoedit file editing permissions—is not enabled by default.
Scope and affected configuration
- Vulnerability type: Time-of-check vs time-of-use (TOCTOU) race condition in sudoedit
- Affected software: sudo-rs, the Rust implementation of sudo
- Attack vector: Local attacker with existing sudoedit permissions for specific files
- Impact: Arbitrary file placement in directories, possible privilege escalation
- Configuration requirement: Only affects systems with fine-grained sudoedit permissions explicitly configured; default installations are not vulnerable
Why it matters
The fix matters for Ubuntu 26.10 early adopters and administrators who have deployed non-default sudoedit configurations. sudo-rs remains a significant project as a memory-safe reimplementation of a critical setuid utility.
Original reference: ubuntu.com →