Уязвимости util-linux

util-linux libblkid DOS extended-partition overflow produces invalid partition metadata

util-linux is a random collection of Linux utilities. Before util-linux 2.41.4, `parse_dos_extended()` in `libblkid/src/partitions/dos.c` computes an extended-partition start sector with 32-bit addition and does not apply the extended-area bounds checks to the first two EBR entries. A local attacker who causes a crafted DOS extended-partition disk image or removable medium to be probed can wrap `cur_start + start` to sector zero and cause libblkid to report a false partition overlapping the MBR. This directly compromises the integrity of the reported partition metadata; disk modification or availability loss requires a separate downstream con

util-linux mount target TOCTOU allows local privilege escalation

util-linux is a random collection of Linux utilities. In util-linux 2.17 through 2.41.6 and 2.42 through 2.42.3, and in 2.42.4 when the legacy `mount(2)` path is used without `/proc`, restricted non-root `mount` requests validate an `/etc/fstab` target before the mount operation re-resolves that pathname. A local low-privileged user authorized by an fstab `user` or `users` entry whose target has an attacker-writable ancestor can use `renameat2(RENAME_EXCHANGE)` to swap a path component and redirect an authorized mount to a root-owned location, such as mounting attacker-controlled content over `/etc/sudoers.d`, and thereby gain root privileges

util-linux libmount Privilege Escalation via Failed Mount Helper

util-linux versions through 2.41.5 and 2.42.2 fail to check mount helper exit status before running post-mount hooks, allowing unprivileged users to execute privileged operations on pre-existing filesystems. Attackers can exploit X-mount.idmap or X-mount.owner hooks to clone filesystems with inherited suid bits or modify target inode permissions after a helper fails, achieving privilege escalation.

Util-linux: util-linux: x-mount.subdir detached-tree resolution can escape via intermediate symlinks

The X-mount.subdir option uses a detached-tree fast path on Linux 6.15 and later and passes the configured subdirectory to open_tree() with AT_SYMLINK_NOFOLLOW. That flag does not stop intermediate symlink traversal or keep resolution inside the newly mounted filesystem. A local unprivileged user with an fstab-authorized X-mount.subdir entry can attach a host path at the intended mountpoint.

Util-linux: util-linux: restricted bind mounts do not pin the source, allowing x-mount.owner/group/mode redirection

A flaw was found in util-linux. Restricted bind mounts take the source path from fstab but do not pin that source before the privileged mount. A local unprivileged user who can replace the authorized source or a writable ancestor can redirect SUID mount(8) to bind another host directory. If the fstab entry also sets X-mount.owner, X-mount.group, or X-mount.mode, root then changes ownership or mode on that redirected inode.

Util-linux: util-linux: nsenter --join-cgroup leaks root cgroup migration authority

The nsenter --join-cgroup option opens the target cgroup.procs file as root and leaves that file descriptor open across later namespace and credential changes and across execve(). Because the kernel checks later cgroup migrations using the credentials from the original open, a program run in an attacker-controlled target can inherit root's ability to move host processes between cgroups. After a privileged operator uses --join-cgroup against that target, an unprivileged user can migrate and terminate unrelated root processes.

Util-linux: util-linux: heap use-after-free in libblkid nested partition probing

A flaw was found in the libblkid library of util-linux. During nested partition probing, the BSD, Minix, Solaris x86, and UnixWare partition probers cache a raw pointer to a parent partition entry in a dynamically allocated array. When subsequent partition additions cause the array to be reallocated, this pointer becomes stale, leading to a heap use-after-free read. An attacker who can present a crafted block device image (for example, via USB insertion or a loop-mounted disk image) can trigger this flaw without user interaction, as libblkid is invoked automatically by udev/udisks as root on block-device hot-plug events. This could lead to li

util-linux: TOCTOU Race Condition in util-linux mount(8) - Loop Device Setup

util-linux is a random collection of Linux utilities. Prior to version 2.41.4, a TOCTOU (Time-of-Check-Time-of-Use) vulnerability has been identified in the SUID binary /usr/bin/mount from util-linux. The mount binary, when setting up loop devices, validates the source file path with user privileges via fork() + setuid() + realpath(), but subsequently re-canonicalizes and opens it with root privileges (euid=0) without verifying that the path has not been replaced between both operations. Neither O_NOFOLLOW, nor inode comparison, nor post-open fstat() are employed. This allows a local unprivileged user to replace the source file with a symlink

util-linux vulnerability

It was discovered that the util-linux su utility did not drop capabilities when being used with the --pty option. While not a security issue by itself, a local attacker could possibly use the su tool to exploit vulnerabilities in other applications.

• Обновитесь до 2.34-0.1ubuntu9.6+esm1

Util-linux: util-linux: heap buffer overread in setpwnam() when processing 256-byte usernames

A flaw was found in util-linux. This vulnerability allows a heap buffer overread when processing 256-byte usernames, specifically within the `setpwnam()` function, affecting SUID (Set User ID) login-utils utilities writing to the password database.