Description
A Time-of-Check to Time-of-Use (TOCTOU) race condition exists in the mkfifo utility of uutils coreutils. The utility creates a FIFO and then performs a path-based chmod to set permissions. A local attacker with write access to the parent directory can swap the newly created FIFO for a symbolic link between these two operations. This redirects the chmod call to an arbitrary file, potentially enabling privilege escalation if the utility is run with elevated privileges.
Problem types
CWE-367: Time-of-Check Time-of-Use (TOCTOU) Race Condition
Product status
Credits
Zellic
References
github.com/uutils/coreutils/issues/10020
www.openwall.com/lists/oss-security/2026/05/04/4
www.openwall.com/lists/oss-security/2026/05/04/5
www.openwall.com/lists/oss-security/2026/05/04/6
github.com/uutils/coreutils/issues/10020