uutils coreutils vulnerabilities

uutils coreutils before version 0.10.0 apply setuid or setgid mode to install destinations before finalizing ownership changes, allowing privileged users to leave setuid executables owned by the privileged invoker when ownership changes fail. Attackers can execute leftover setuid files with elevated privileges when ownership change operations fail on capability-restricted systems.

A logic error in the cut utility of uutils coreutils causes it to ignore the -s (only-delimited) flag when -z (null-terminated) and -d '' (empty delimiter) are used together. The implementation routes this combination through a specialized newline-delimiter code path that fails to check record suppression, so cut emits the entire record plus a NUL byte instead of suppressing it.

A logic error in the cut utility of uutils coreutils causes the program to incorrectly interpret the literal two-byte string '' (two single quotes) as an empty delimiter. The implementation mistakenly maps this string to the NUL character for both the -d and --output-delimiter options. This can lead to silent data corruption or logic errors in automated scripts and data pipelines.

A logic error in the tr utility of uutils coreutils incorrectly defines the [:graph:] and [:print:] character classes. The implementation mistakenly includes the ASCII space (0x20) in [:graph:] and excludes it from [:print:], reversing POSIX and GNU coreutils behavior. This can lead to unintended data modification or loss in automation scripts.

A logic error in the expr utility of uutils coreutils causes parenthesized subexpressions to be evaluated during parsing rather than execution. This prevents proper short-circuiting for logical OR (|) and AND (&), so arithmetic errors in branches that should be skipped are raised as fatal errors. This diverges from GNU expr behavior and can cause premature shell script termination.

A logic error in the env utility of uutils coreutils causes incorrect parsing of command-line arguments when using the -S (split-string) option. Unlike GNU env, the uutils implementation incorrectly validates sequences, resulting in an "invalid sequence" error and immediate termination with exit status 125 when encountering valid but unrecognized sequences like \a or \x.

A Time-of-Check to Time-of-Use (TOCTOU) vulnerability exists in the chcon utility of uutils coreutils during recursive operations. The implementation resolves recursive targets using a fresh path lookup (via fts_accpath) rather than binding traversal and label application to the directory state encountered during traversal; because operations are not anchored to file descriptors, a local attacker with write access to a directory tree can exploit timing-sensitive rename or symlink races to redirect a privileged recursive relabeling operation to unintended files or directories. This breaks SELinux administration hardening expectations and can lead to unauthorized modification of security labels on sensitive system objects.

A logic error in the split utility of uutils coreutils corrupts output filenames when given non-UTF-8 prefixes or suffixes. The implementation uses to_string_lossy(), replacing invalid byte sequences with the UTF-8 replacement character (U+FFFD), unlike GNU split which preserves raw bytes. This leads to files with incorrect names.

A Time-of-Check to Time-of-Use (TOCTOU) vulnerability exists in the split utility of uutils coreutils. The program checks identity between input and output files using their paths before initiating the split operation, but subsequently opens the output file with truncation after this path-based validation. A local attacker with write access to the directory can exploit this race window by manipulating mutable path components (e.g., swapping a path with a symbolic link), causing split to truncate and write to an unintended target file, potentially including the input file itself or other sensitive files accessible to the process, leading to permanent data loss.

A logic error in the ln utility of uutils coreutils causes rejection of source paths containing non-UTF-8 filename bytes when using target-directory forms (e.g., ln SOURCE... DIRECTORY). Unlike GNU ln, the uutils implementation enforces UTF-8 encoding, resulting in a stat failure and non-zero exit code.

A logic error in the ln utility of uutils coreutils causes it to dereference a symbolic link target even when --no-dereference (or -n) is explicitly provided. The implementation only honored the no-dereference intent when --force was also enabled. This flaw causes ln to follow a symlink pointing to a directory and create new links inside that target directory instead of treating the symlink itself as the destination. In environments where a privileged user or system script uses ln -n to update a symlink, a local attacker could manipulate existing symlinks to redirect file creation into sensitive directories.

The id utility in uutils coreutils produces incorrect pretty-print output when the real UID and effective UID differ. It incorrectly uses the effective GID instead of the effective UID for the effective user name lookup, resulting in misleading diagnostics.

The id utility in uutils coreutils miscalculates the groups= section of its output by using a user's real GID instead of their effective GID to compute the group list. This can diverge from GNU coreutils, and because many scripts and automated processes rely on id output for security-critical access-control or permission decisions, the discrepancy can lead to unauthorized access or security misconfigurations.

An argument parsing error in the kill utility of uutils coreutils incorrectly interprets kill -1 as a request to send the default signal (SIGTERM) to PID -1. Sending a signal to PID -1 causes the kernel to terminate all processes visible to the caller, potentially leading to a system crash or massive process termination.

The nohup utility in uutils coreutils creates its default output file, nohup.out, without explicit restricted permissions, inheriting umask-based permissions (typically 0644, world-readable). In multi-user environments, this allows any user to read the captured stdout/stderr output of a command.

The printenv utility in uutils coreutils fails to display environment variables containing invalid UTF-8 byte sequences. The implementation silently skips these entries rather than printing raw bytes, allowing malicious environment variables (e.g., adversarial LD_PRELOAD values) to evade inspection.

The mv utility in uutils coreutils improperly handles directory trees containing symbolic links during moves across filesystem boundaries. Instead of preserving symlinks, the implementation expands them, copying the linked targets as real files or directories at the destination. This can lead to resource exhaustion, unexpected duplication of sensitive data, or infinite recursion with symlink loops.

A TOCTOU race condition exists in the mv utility of uutils coreutils during cross-device operations. The utility removes the destination path before recreating it, allowing a local attacker with write access to substitute a symlink and overwrite an arbitrary target file.

The rm utility in uutils coreutils allows bypass of safeguards protecting the current directory. While it correctly refuses to delete . or .., it fails to recognize equivalent paths with trailing slashes (e.g., ./ or .///), so executing rm -rf ./ silently recursively deletes all contents of the current directory.

The safe_traversal module in uutils coreutils, which protects against Time-of-Check to Time-of-Use (TOCTOU) symlink races using file-descriptor-relative syscalls, is incorrectly limited to Linux targets. On other Unix-like systems such as macOS and FreeBSD, the utility fails to use these protections, leaving directory traversal operations vulnerable to symlink race conditions.

The mknod utility in uutils coreutils fails to handle security labels atomically, creating device nodes before setting the SELinux context. If labeling fails, it attempts cleanup with std::fs::remove_dir, which cannot remove device nodes or FIFOs, leaving mislabeled nodes with incorrect default contexts.

The touch utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file creation. When the utility identifies a missing path, it later attempts creation using File::create(), which internally uses O_TRUNC. An attacker can exploit this window to create a file or swap a symlink at the target path, causing touch to truncate an existing file and leading to permanent data loss.

A Time-of-Check to Time-of-Use (TOCTOU) vulnerability in the cp utility of uutils coreutils allows an attacker to bypass no-dereference intent. The utility checks if a source path is a symbolic link using path-based metadata but subsequently opens it without the O_NOFOLLOW flag. An attacker with concurrent write access can swap a regular file for a symbolic link during this window, causing a privileged cp process to copy the contents of arbitrary sensitive files into a destination controlled by the attacker.

The cp utility in uutils coreutils, when performing recursive copies (-R), incorrectly treats character and block device nodes as stream sources rather than preserving them. Because the implementation reads bytes into regular files at the destination instead of using mknod, device semantics are destroyed (e.g., /dev/null becomes a regular file), which can lead to runtime denial of service through disk exhaustion or process hangs when reading from unbounded device nodes.

The cp utility in uutils coreutils is vulnerable to an information disclosure race condition. Destination files are created with umask-derived permissions before being restricted to their final mode, allowing a local attacker to race and open the file.

A Time-of-Check to Time-of-Use (TOCTOU) vulnerability exists in the install utility of uutils coreutils when using the -D flag. The command creates parent directories and then performs a second path resolution to create the target file, neither anchored to a directory file descriptor. An attacker with concurrent write access can replace a path component with a symbolic link between these operations, redirecting the privileged write to an arbitrary file system location.

The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. It unlinks an existing destination file and recreates it without the O_EXCL flag, allowing a local attacker to swap the path with a symbolic link and redirect privileged writes to overwrite arbitrary system files.

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.

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 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.

A TOCTOU race condition exists in the mkfifo utility of uutils coreutils. A local attacker with write access to the parent directory can swap the newly created FIFO for a symbolic link, potentially leading to privilege escalation.

The mv utility in uutils coreutils fails to preserve file ownership during moves across different filesystem boundaries. The utility falls back to a copy-and-delete routine that creates the destination file using the caller's UID/GID rather than the source's metadata. This breaks backups and migrations, causing files moved by a privileged user (e.g., root) to become root-owned unexpectedly, which can lead to information disclosure or restricted access for the intended owners.

The cp utility in uutils coreutils fails to properly handle setuid and setgid bits when ownership preservation fails. When copying with the -p (preserve) flag, the utility applies the source mode bits even if the chown operation is unsuccessful. This can result in a user-owned copy retaining original privileged bits, creating unexpected privileged executables that violate local security policies. This differs from GNU cp, which clears these bits when ownership cannot be preserved.

A vulnerability in the rm utility of uutils coreutils allows bypassing the --preserve-root protection. The implementation uses a path-string check rather than comparing device and inode numbers, allowing an attacker or accidental user to bypass the safeguard via a symbolic link resolving to the root directory.

The sort utility in uutils coreutils is vulnerable to a process panic when using the --files0-from option with inputs containing non-UTF-8 filenames. The implementation enforces UTF-8 encoding and utilizes expect(), causing an immediate crash when encountering valid but non-UTF-8 paths. This diverges from GNU sort, which treats filenames as raw bytes. A local attacker can exploit this to crash the utility and disrupt automated pipelines.

The comm utility in uutils coreutils reads from non-regular file inputs before performing comparison. The are_files_identical function opens and reads both inputs without first verifying they are regular files, causing silent data loss for FIFOs or pipes and potential hangs on infinite streams like /dev/zero.

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.

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.

The dd utility in uutils coreutils suppresses errors during file truncation 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.

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 check the only_delimited flag in cut_fields_newline_char_delim, causing non-delimited lines to be printed when they should be suppressed. This can pass unexpected data to downstream scripts.

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 empty, the uutils implementation treats the empty string as a valid path, creating temporary files in the current working directory instead of the intended secure temporary directory. If the CWD is more permissive or accessible to other users than /tmp, this may lead to unintended information disclosure or unauthorized access to temporary data.

A flaw in ChownExecutor in uutils coreutils chown and chgrp returns an incorrect exit code during recursive operations. The exit code depends only on the last processed file, masking permission errors on earlier files if the last succeeds.

The recursive mode (-R) of chmod in uutils coreutils mishandles exit codes with multiple files. The return value depends only on the last file, so errors like 'Operation not permitted' on earlier files are masked by the last file's success.