Uutils: Security Vulnerabilities
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.
CVSS Score
7.0
EPSS Score
0.0
Published
2026-04-22
The mkdir utility in uutils coreutils incorrectly applies permissions when using the -m flag by creating a directory with umask-derived permissions (typically 0755) before subsequently changing them to the requested mode via a separate chmod system call. In multi-user environments, this introduces a brief window where a directory intended to be private is accessible to other users, potentially leading to unauthorized data access.
CVSS Score
3.3
EPSS Score
0.0
Published
2026-04-22
A Time-of-Check to Time-of-Use (TOCTOU) vulnerability exists in the mv utility of uutils coreutils during cross-device moves. The extended attribute (xattr) preservation logic uses multiple path-based system calls that perform fresh path-to-inode lookups for each operation. A local attacker with write access to the directory can exploit this race to swap files between calls, causing the destination file to receive an inconsistent mix of security xattrs, such as SELinux labels or file capabilities.
CVSS Score
4.7
EPSS Score
0.0
Published
2026-04-22
The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.
CVSS Score
6.3
EPSS Score
0.0
Published
2026-04-22
A vulnerability in uutils coreutils mkfifo allows for the unauthorized modification of permissions on existing files. When mkfifo fails to create a FIFO because a file already exists at the target path, it fails to terminate the operation for that path and continues to execute a follow-up set_permissions call. This results in the existing file's permissions being changed to the default mode (often 644 after umask), potentially exposing sensitive files such as SSH private keys to other users on the system.
CVSS Score
7.1
EPSS Score
0.0
Published
2026-04-22
The mktemp utility in uutils coreutils fails to properly handle an empty TMPDIR environment variable. Unlike GNU mktemp, which falls back to /tmp when TMPDIR is an empty string, the uutils implementation treats the empty string as a valid path. This causes temporary files to be created in the current working directory (CWD) instead of the intended secure temporary directory. If the CWD is more permissive or accessible to other users than /tmp, it may lead to unintended information disclosure or unauthorized access to temporary data.
CVSS Score
3.3
EPSS Score
0.0
Published
2026-04-22
The cut utility in uutils coreutils incorrectly handles the -s (only-delimited) option when a newline character is specified as the delimiter. The implementation fails to verify the only_delimited flag in the cut_fields_newline_char_delim function, causing the utility to print non-delimited lines that should have been suppressed. This can lead to unexpected data being passed to downstream scripts that rely on strict output filtering.
CVSS Score
3.3
EPSS Score
0.0
Published
2026-04-22
The dd utility in uutils coreutils suppresses errors during file truncation operations by unconditionally calling Result::ok() on truncation attempts. While intended to mimic GNU behavior for special files like /dev/null, the uutils implementation also hides failures on regular files and directories caused by full disks or read-only file systems. This can lead to silent data corruption in backup or migration scripts, as the utility may report a successful operation even when the destination file contains old or garbage data.
CVSS Score
3.3
EPSS Score
0.0
Published
2026-04-22
A vulnerability in the tail utility of uutils coreutils allows for the exfiltration of sensitive file contents when using the --follow=name option. Unlike GNU tail, the uutils implementation continues to monitor a path after it has been replaced by a symbolic link, subsequently outputting the contents of the link's target. In environments where a privileged user (e.g., root) monitors a log directory, a local attacker with write access to that directory can replace a log file with a symlink to a sensitive system file (such as /etc/shadow), causing tail to disclose the contents of the sensitive file.
CVSS Score
5.3
EPSS Score
0.0
Published
2026-04-22
The comm utility in uutils coreutils silently corrupts data by performing lossy UTF-8 conversion on all output lines. The implementation uses String::from_utf8_lossy(), which replaces invalid UTF-8 byte sequences with the Unicode replacement character (U+FFFD). This behavior differs from GNU comm, which processes raw bytes and preserves the original input. This results in corrupted output when the utility is used to compare binary files or files using non-UTF-8 legacy encodings.
CVSS Score
3.3
EPSS Score
0.0
Published
2026-04-22