Description
Screen version 5.0.0 and older version 4 releases have a TOCTOU race potentially allowing to send SIGHUP, SIGCONT to privileged processes when installed setuid-root.
Published: 2025-05-26
Score: 5.7 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2025-28070 Screen version 5.0.0 and older version 4 releases have a TOCTOU race potentially allowing to send SIGHUP, SIGCONT to privileged processes when installed setuid-root.
Ubuntu USN Ubuntu USN USN-7978-1 GNU Screen vulnerabilities
History

Tue, 27 May 2025 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 26 May 2025 13:30:00 +0000

Type Values Removed Values Added
Description A flaw was found in Screen. A possible denial of service caused by race conditions when sending signals exists. The `CheckPid()` function drops privileges to the real user ID and tests whether the kernel can send a signal to the target PID using these credentials. The signal is sent later via `Kill()`, potentially using full root privileges. By this time, the previously checked PID could have been replaced by a different, privileged process. It might also be possible to trick the privileged Screen daemon process into sending signals to itself since a process is always allowed to send signals to itself. Screen version 5.0.0 and older version 4 releases have a TOCTOU race potentially allowing to send SIGHUP, SIGCONT to privileged processes when installed setuid-root.
Title screen: Race Conditions when Sending Signals Screen has a TOCTOU race potentially allowing to send SIGHUP, SIGCONT to privileged processes when installed setuid-root
Weaknesses CWE-367
References
Metrics cvssV4_0

{'score': 5.7, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Wed, 14 May 2025 02:30:00 +0000

Type Values Removed Values Added
Description A flaw was found in Screen. A possible denial of service caused by race conditions when sending signals exists. The `CheckPid()` function drops privileges to the real user ID and tests whether the kernel can send a signal to the target PID using these credentials. The signal is sent later via `Kill()`, potentially using full root privileges. By this time, the previously checked PID could have been replaced by a different, privileged process. It might also be possible to trick the privileged Screen daemon process into sending signals to itself since a process is always allowed to send signals to itself.
Title screen: Race Conditions when Sending Signals
Weaknesses CWE-362
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: suse

Published:

Updated: 2025-05-27T14:10:49.034Z

Reserved: 2025-04-30T11:28:04.728Z

Link: CVE-2025-46805

cve-icon Vulnrichment

Updated: 2025-05-27T14:10:41.871Z

cve-icon NVD

Status : Deferred

Published: 2025-05-26T14:15:20.037

Modified: 2026-04-15T00:35:42.020

Link: CVE-2025-46805

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-05-12T00:00:00Z

Links: CVE-2025-46805 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses