Screen <5.0.0 TOCTOU race allows SIGHUP/SIGCONT to privileged processes
CVE-2025-46805 Published on May 26, 2025
Screen has a TOCTOU race potentially allowing to send SIGHUP, SIGCONT to privileged processes when installed setuid-root
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.
Vulnerability Analysis
CVE-2025-46805 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a TOCTTOU Vulnerability?
The software checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the software to perform invalid actions when the resource is in an unexpected state. This weakness can be security-relevant when an attacker can influence the state of the resource between check and use. This can happen with shared resources such as files, memory, or even variables in multithreaded programs.
CVE-2025-46805 has been classified to as a TOCTTOU vulnerability or weakness.
Products Associated with CVE-2025-46805
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Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.