Описание
A flaw was found in systemd-tmpfiles. When processing a tmpfiles.d configuration entry that writes to a file, systemd-tmpfiles can follow a symbolic link placed by an unprivileged local user, and an existing safety check does not detect this specific case because it always treats transitions away from the root user as safe. On systems where a tmpfiles.d configuration targets a path an unprivileged user can influence, this could allow that user to redirect a privileged systemd-tmpfiles write to a file of their choosing, though the content written remains determined by the existing configuration rather than by the unprivileged user. The highest threat from this vulnerability is to integrity.
A flaw was found in systemd-tmpfiles. When processing a tmpfiles.d configuration entry that writes to a file, systemd-tmpfiles can follow a symbolic link placed by an unprivileged local user, and an existing safety check does not detect this specific case because it always treats transitions away from the root user as safe. On systems where a tmpfiles.d configuration targets a path an unprivileged user can influence, this could allow that user to redirect a privileged systemd-tmpfiles write to a file of their choosing, though the content written remains determined by the existing configuration rather than by the unprivileged user. The highest threat from this vulnerability is to integrity.
Ссылки
- https://nvd.nist.gov/vuln/detail/CVE-2026-16552
- https://access.redhat.com/security/cve/CVE-2026-16552
- https://bugzilla.redhat.com/show_bug.cgi?id=2506073
- https://github.com/systemd/systemd/blob/b9ef5951f8f9e156479494fdb9ca6274cb3d3c53/src/basic/chase.c
- https://github.com/systemd/systemd/blob/b9ef5951f8f9e156479494fdb9ca6274cb3d3c53/src/tmpfiles/tmpfiles.c
Связанные уязвимости
[REJECTED] A flaw was found in systemd-tmpfiles. When processing a tmpfiles.d configuration entry that writes to a file, systemd-tmpfiles can follow a symbolic link placed by an unprivileged local user, and an existing safety check does not detect this specific case because it always treats transitions away from the root user as safe. On systems where a tmpfiles.d configuration targets a path an unprivileged user can influence, this could allow that user to redirect a privileged systemd-tmpfiles write to a file of their choosing, though the content written remains determined by the existing configuration rather than by the unprivileged user. The highest threat from this vulnerability is to integrity.
Rejected reason: The reported issue is invalid, as it requires root privileges to reproduce, and it is out of scope of the threat model of the affected component.