Util Linux
Monthly
Local privilege escalation in the SUID-root mount(8) utility shipped with util-linux 2.39.1 through 2.41.4 and 2.42 through 2.42.1, where the attacker-controlled LIBMOUNT_FORCE_MOUNT2 environment variable is read with getenv() and can force the legacy, non-atomic multi-step bind-mount path. On hosts whose /etc/fstab contains a bind mount authorized for unprivileged use via the user or users option and hardened with nosuid, noexec, or nodev, a local low-privileged user can win a timing race between the initial bind mount and the follow-up remount that applies those protective flags, briefly exposing an unprotected mount from which a SUID binary can be executed to obtain root. Exploitation is conditional (it requires that specific non-default fstab configuration) and non-deterministic because it depends on a race window; no public exploit code was identified at time of analysis and the issue is not confirmed as actively exploited (CISA KEV). Vendor-released patches are available in util-linux 2.41.5 and 2.42.2.
Local privilege escalation to root in util-linux's libmount affects versions 2.17 through 2.41.6 and 2.42 through 2.42.3, and also 2.42.4 when the legacy mount(2) path is used without /proc available. A local, low-privileged user who is already authorized by an /etc/fstab entry carrying the user or users option can exploit a time-of-check/time-of-use race: libmount validates the fstab target path and then the mount operation re-resolves that pathname, so an attacker who controls a writable ancestor directory can use renameat2(RENAME_EXCHANGE) to swap a path component and redirect the authorized mount to a root-owned location such as /etc/sudoers.d, gaining root. Exploitation is local only, requires the attacker to already hold an fstab mount authorization plus a writable ancestor on the configured target, and depends on winning the race (assessed AC:H), so it is non-deterministic; patched code paths using the new mount API (2.41.5 / 2.42.2 and later) or 2.42.4 with /proc present are not affected, and no public exploit identified at time of analysis.
Local privilege escalation in util-linux's SUID mount utility affects versions 2.39 through 2.41.4 and 2.42 through 2.42.1: a local, already-authorized low-privileged user can win a narrow timing race in the post-mount hook and redirect a privileged chmod()/lchown() onto a root-owned path, potentially obtaining root privileges. Exploitation requires a non-default /etc/fstab entry that combines the 'user' or 'users' mount option with an X-mount.mode, X-mount.owner, or X-mount.group option, plus write access to a writable ancestor directory of the mount target; the race itself is difficult (CVSS 3.1 7.0, AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H). No public exploit code or confirmed active exploitation has been identified at time of analysis, and the vendor has released fixes in 2.41.5 and 2.42.2.
Privilege escalation in util-linux through versions 2.41.5 and 2.42.2 allows local low-privilege users to execute privileged post-mount hook operations on pre-existing filesystems by exploiting libmount's failure to validate mount helper exit status before dispatching the MOUNT_POST stage. The root cause - captured by CWE-390 - lies in context_mount.c functions mnt_context_do_mount() and mnt_context_mount(), which gate post-mount hook execution solely on a zero result code without verifying whether the underlying mount helper or kernel syscall actually succeeded. No public exploit code has been identified at time of analysis, but the public GHSA advisory and three upstream patch commits provide sufficient technical detail to support independent exploit development.
Unauthorized read access to root-owned files via TOCTOU race condition in util-linux mount binary (versions prior to 2.41.4) allows local users with existing fstab entries to replace loop device source files with symlinks pointing to sensitive files or block devices, bypassing intended access controls. The vulnerability requires moderate exploitation effort (AC:H) and authenticated user access (PR:L) but grants disclosure of confidential data including filesystem backups and disk volumes. No public exploit code or active CISA KEV status identified at time of analysis.
wall in util-linux through 2.40, often installed with setgid tty permissions, allows escape sequences to be sent to other users' terminals through argv. Rated low severity (CVSS 3.3), this vulnerability is low attack complexity. Public exploit code available and EPSS exploitation probability 10.2%.
A flaw was found in the util-linux chfn and chsh utilities when compiled with Readline support. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
An integer overflow in util-linux through 2.37.1 can potentially cause a buffer overflow if an attacker were able to use system resources in a way that leads to a large number in the. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
In util-linux before 2.32-rc1, bash-completion/umount allows local users to gain privileges by embedding shell commands in a mountpoint name, which is mishandled during a umount command (within Bash). Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
The mkostemp function in login-utils in util-linux when used incorrectly allows remote attackers to cause file name collision and possibly other attacks. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
The parse_dos_extended function in partitions/dos.c in the libblkid library in util-linux allows physically proximate attackers to cause a denial of service (memory consumption) via a crafted MSDOS. Rated medium severity (CVSS 4.6), this vulnerability is no authentication required, low attack complexity.
Blkid in util-linux before 2.26rc-1 allows local users to execute arbitrary code. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. This Command Injection vulnerability could allow attackers to inject arbitrary commands into system command execution.
runuser in util-linux allows local users to escape to the parent session via a crafted TIOCSTI ioctl call, which pushes characters to the terminal's input buffer. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Buffer overflow in text-utils/colcrt.c in colcrt in util-linux before 2.27 allows local users to cause a denial of service (crash) via a crafted file, related to the page global variable. Rated low severity (CVSS 2.1), this vulnerability is low attack complexity. Public exploit code available.
(a) mount and (b) umount in util-linux 2.14.1, 2.17.2, and probably other versions allow local users to determine the existence of restricted directories by (1) using the --guess-fstype command-line. Rated low severity (CVSS 2.1), this vulnerability is low attack complexity. No vendor patch available.
Local privilege escalation in the SUID-root mount(8) utility shipped with util-linux 2.39.1 through 2.41.4 and 2.42 through 2.42.1, where the attacker-controlled LIBMOUNT_FORCE_MOUNT2 environment variable is read with getenv() and can force the legacy, non-atomic multi-step bind-mount path. On hosts whose /etc/fstab contains a bind mount authorized for unprivileged use via the user or users option and hardened with nosuid, noexec, or nodev, a local low-privileged user can win a timing race between the initial bind mount and the follow-up remount that applies those protective flags, briefly exposing an unprotected mount from which a SUID binary can be executed to obtain root. Exploitation is conditional (it requires that specific non-default fstab configuration) and non-deterministic because it depends on a race window; no public exploit code was identified at time of analysis and the issue is not confirmed as actively exploited (CISA KEV). Vendor-released patches are available in util-linux 2.41.5 and 2.42.2.
Local privilege escalation to root in util-linux's libmount affects versions 2.17 through 2.41.6 and 2.42 through 2.42.3, and also 2.42.4 when the legacy mount(2) path is used without /proc available. A local, low-privileged user who is already authorized by an /etc/fstab entry carrying the user or users option can exploit a time-of-check/time-of-use race: libmount validates the fstab target path and then the mount operation re-resolves that pathname, so an attacker who controls a writable ancestor directory can use renameat2(RENAME_EXCHANGE) to swap a path component and redirect the authorized mount to a root-owned location such as /etc/sudoers.d, gaining root. Exploitation is local only, requires the attacker to already hold an fstab mount authorization plus a writable ancestor on the configured target, and depends on winning the race (assessed AC:H), so it is non-deterministic; patched code paths using the new mount API (2.41.5 / 2.42.2 and later) or 2.42.4 with /proc present are not affected, and no public exploit identified at time of analysis.
Local privilege escalation in util-linux's SUID mount utility affects versions 2.39 through 2.41.4 and 2.42 through 2.42.1: a local, already-authorized low-privileged user can win a narrow timing race in the post-mount hook and redirect a privileged chmod()/lchown() onto a root-owned path, potentially obtaining root privileges. Exploitation requires a non-default /etc/fstab entry that combines the 'user' or 'users' mount option with an X-mount.mode, X-mount.owner, or X-mount.group option, plus write access to a writable ancestor directory of the mount target; the race itself is difficult (CVSS 3.1 7.0, AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H). No public exploit code or confirmed active exploitation has been identified at time of analysis, and the vendor has released fixes in 2.41.5 and 2.42.2.
Privilege escalation in util-linux through versions 2.41.5 and 2.42.2 allows local low-privilege users to execute privileged post-mount hook operations on pre-existing filesystems by exploiting libmount's failure to validate mount helper exit status before dispatching the MOUNT_POST stage. The root cause - captured by CWE-390 - lies in context_mount.c functions mnt_context_do_mount() and mnt_context_mount(), which gate post-mount hook execution solely on a zero result code without verifying whether the underlying mount helper or kernel syscall actually succeeded. No public exploit code has been identified at time of analysis, but the public GHSA advisory and three upstream patch commits provide sufficient technical detail to support independent exploit development.
Unauthorized read access to root-owned files via TOCTOU race condition in util-linux mount binary (versions prior to 2.41.4) allows local users with existing fstab entries to replace loop device source files with symlinks pointing to sensitive files or block devices, bypassing intended access controls. The vulnerability requires moderate exploitation effort (AC:H) and authenticated user access (PR:L) but grants disclosure of confidential data including filesystem backups and disk volumes. No public exploit code or active CISA KEV status identified at time of analysis.
wall in util-linux through 2.40, often installed with setgid tty permissions, allows escape sequences to be sent to other users' terminals through argv. Rated low severity (CVSS 3.3), this vulnerability is low attack complexity. Public exploit code available and EPSS exploitation probability 10.2%.
A flaw was found in the util-linux chfn and chsh utilities when compiled with Readline support. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
An integer overflow in util-linux through 2.37.1 can potentially cause a buffer overflow if an attacker were able to use system resources in a way that leads to a large number in the. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
In util-linux before 2.32-rc1, bash-completion/umount allows local users to gain privileges by embedding shell commands in a mountpoint name, which is mishandled during a umount command (within Bash). Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
The mkostemp function in login-utils in util-linux when used incorrectly allows remote attackers to cause file name collision and possibly other attacks. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
The parse_dos_extended function in partitions/dos.c in the libblkid library in util-linux allows physically proximate attackers to cause a denial of service (memory consumption) via a crafted MSDOS. Rated medium severity (CVSS 4.6), this vulnerability is no authentication required, low attack complexity.
Blkid in util-linux before 2.26rc-1 allows local users to execute arbitrary code. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. This Command Injection vulnerability could allow attackers to inject arbitrary commands into system command execution.
runuser in util-linux allows local users to escape to the parent session via a crafted TIOCSTI ioctl call, which pushes characters to the terminal's input buffer. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Buffer overflow in text-utils/colcrt.c in colcrt in util-linux before 2.27 allows local users to cause a denial of service (crash) via a crafted file, related to the page global variable. Rated low severity (CVSS 2.1), this vulnerability is low attack complexity. Public exploit code available.
(a) mount and (b) umount in util-linux 2.14.1, 2.17.2, and probably other versions allow local users to determine the existence of restricted directories by (1) using the --guess-fstype command-line. Rated low severity (CVSS 2.1), this vulnerability is low attack complexity. No vendor patch available.