CVE-2025-23395 Local root exploit via `logfile_reopen()` in screen 5.0.0 with setuid-root bit set
Unprivileged users can escalate to root by exploiting a privilege dropping failure in GNU Screen when setuid-root is enabled.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-23395?
CVE-2025-23395 is a high-severity vulnerability, published on 26 May 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Screen 5.0.0 when it runs with setuid-root privileges does not drop privileges while operating on a user supplied path. This allows unprivileged users to create files in arbitrary locations with `root` ownership, the invoking user's (real) group ownership and file mode 0644. All data written to the Screen PTY will be logged into this file, allowing to escalate to root privileges
Weakness: CWE-271
Which versions are affected by CVE-2025-23395?
How do I fix CVE-2025-23395?
Apply the vendor's patch.
Is CVE-2025-23395 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-23395 exists.
Sources
Also known as ALPINE-CVE-2025-23395, BELL-CVE-2025-23395, GHSA-84g7-x869-xfgv.