Local root exploit via `logfile_reopen()` in screen 5.0.0 with setuid-root bit set
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
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
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | screen | 5.0 – 5.0.0 | — | No fix listed | CNA |
- screen Vendor— Affected 5.0 – 5.0.0 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2025-23395
- 2026-10-03 Alias added: GHSA-84g7-x869-xfgv
References
Sources
- CVE-2025-23395 · CVE Program
- CVE-2025-23395 · NVD
- FIRST EPSS
- GHSA-84g7-x869-xfgv · GitHub Advisory Database · CC BY 4.0
- CVE-2025-23395 · Red Hat security data · CC BY 4.0
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