Gnu ≫ Screen

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 owne...

The default mode of pseudo terminals (PTYs) allocated by Screen was changed from 0620 to 0622, thereby allowing anyone to write to any Screen PTYs in the system.

A minor information leak when running Screen with setuid-root privileges allows unprivileged users to deduce information about a path that would otherwise not be available. Affected are older Screen versions, as well as version 5.0.0.

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.

socket.c in GNU Screen through 4.9.0, when installed setuid or setgid (the default on platforms such as Arch Linux and FreeBSD), allows local users to send a privileged SIGHUP signal to any PID, causing a denial of service or disruption of the target...

encoding.c in GNU Screen through 4.8.0 allows remote attackers to cause a denial of service (invalid write access and application crash) or possibly have unspecified other impact via a crafted UTF-8 character sequence.

A buffer overflow was found in the way GNU Screen before 4.8.0 treated the special escape OSC 49. Specially crafted output, or a special program, could corrupt memory and crash Screen or possibly have unspecified other impact.

GNU screen before 4.5.1 allows local users to modify arbitrary files and consequently gain root privileges by leveraging improper checking of logfile permissions.

GNU screen 4.0.3 creates the /tmp/screen-exchange temporary file with world-readable permissions, which might allow local users to obtain sensitive session information.

GNU screen 4.0.3 allows local users to unlock the screen via a CTRL-C sequence at the password prompt. NOTE: multiple third parties report inability to reproduce this issue