The vulnerability in the uutils coreutils mkfifo command allows an attacker to change the permissions of an existing file after the creation of a FIFO fails. When a FIFO cannot be created because a file already exists at the target path, mkfifo does not abort the operation and proceeds to call set_permissions on that file. The permissions are then set to the default mode derived from the umask, often 0644. This behavior can expose sensitive files, such as SSH private keys, to other users. The weakness is a failure to enforce expected access controls (CWE-732).

The affected product is uutils coreutils, specifically the mkfifo utility. No version information is enumerated in the data, so any installation of uutils coreutils that implements the flawed mkfifo logic may be vulnerable.

The CVSS score for this issue is 7.1, indicating a high severity. No EPSS score is available, and the vulnerability is not listed in CISA’s KEV catalog. An attacker would typically need local write access to a directory where a file already exists so that the mkfifo operation fails and the follow‑up permission change is applied. The inferred attack vector is local, and the impact can lead to unauthorized file access if sensitive files become world readable.