The following vulnerability in util-linux was announced (taken from http://seclists.org/oss-sec/2015/q3/423):

""" If the chfn and chsh binaries (both setuid-root) from util-linux/login-utils are compiled WITHOUT libuser support, they eventually call mkostemp(localtmp, ORDWR|OCREAT|OEXCL|OCLOEXEC); where localtmp is "/etc/%s.XXXXXX" and %s is progname (i.e., argv[0]'s basename).

An attacker could repeatedly execve chfn as "ld.so" until mkostemp() creates "/etc/ld.so.preload" (after a few days, in our tests). This particular example doesn't actually work, because "preload" is 7 chars and "XXXXXX" is 6 chars, but it seems there are other interesting possibilities, like "/etc/rc.status" and "/etc/krb5.keytab".

The impact of this vulnerability is probably very limited: most Linux distributions ship either the chfn/chsh binaries from the shadow-utils (NOT the login-utils ones), or the login-utils ones but WITH libuser support. """

Upstream patch: https://github.com/karelzak/util-linux/commit/bde91c85bdc77975155058276f99d2e0f5eab5a9

In the Linux kernel, the following vulnerability has been resolved:

KVM: SEV: Compute the correct max length of the in-GHCB scratch area

When setting the length of the GHCB scratch area, and the area is in the GHCB shared buffer, set the effective length of the scratch area to the max possible size given the start of the guest-provided pointer, and the end of the shared buffer.

The code was "fine" when first introduced, as KVM doesn't consult the length of the buffer when emulating MMIO, because the passed in @len always specifies the max size required. But for PSC requests, the incoming @len is just the minimum length (to process the header), and KVM needs to know the full size of the scratch area to avoid buffer overflows (spoiler alert).

Opportunistically rename @len => @minlen to better reflect its role.

A incorrect variable in a SUSE specific patch for pamaccess rule matching in PAM 1.3.0 in openSUSE Leap 15.0 and SUSE Linux Enterprise 15 could lead to pamaccess rules not being applied (fail open).

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) by a different user, as demonstrated by logging in as root and entering umount followed by a tab character for autocompletion.

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.

Blkid in util-linux before 2.26rc-1 allows local users to execute arbitrary code.

Common Vulnerabilities and Exposures assigned an identifier CVE-2007-5191 to the following vulnerability:

mount and umount in util-linux call the setuid and setgid functions in the wrong order and do not check the return values, which might allow attackers to gain privileges via helpers such as mount.nfs.

References: http://git.kernel.org/?p=utils/util-linux-ng/util-linux-ng.git;a=commit;h=ebbeb2c7ac1b00b6083905957837a271e80b187e

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 limited information disclosure or denial of service.

An issue was discovered in hwclock.13-v2.27 allows attackers to gain escalated privlidges or execute arbitrary commands via the path parameter when setting the date.

A flaw was found in the Linux kernel SELinux LSM hook implementation before version 5.7, where it incorrectly assumed that an skb would only contain a single netlink message. The hook would incorrectly only validate the first netlink message in the skb and allow or deny the rest of the messages within the skb with the granted permission without further processing.

At this time, there is no known ability for an attacker to use this to abuse this flaw as capabilities are required to process any 'modify' operation.

script command in the util-linux package before 2.11n allows local users to overwrite arbitrary files by setting a hardlink from the typescript log file to any file on the system, then having root execute the script command.

DISPUTED 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 /proc/sysvipc/sem file. NOTE: this is unexploitable in GNU C Library environments, and possibly in all realistic environments.

A flaw was found in the util-linux chfn and chsh utilities when compiled with Readline support. The Readline library uses an "INPUTRC" environment variable to get a path to the library config file. When the library cannot parse the specified file, it prints an error message containing data from the file. This flaw allows an unprivileged user to read root-owned files, potentially leading to privilege escalation. This flaw affects util-linux versions prior to 2.37.4.

A flaw was found in util-linux's libmount. An issue related to parsing the /proc/self/mountinfo file allows an unprivileged user to unmount other users' filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory.

A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows an unprivileged local attacker to unmount FUSE filesystems that belong to certain other users who have a UID that is a prefix of the UID of the attacker in its string form. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.

Insyde IHISI function 0x49 can restore factory defaults for certain UEFI variables without further authentication by default, which could lead to a possible roll-back attack in certain platforms. This is fixed in: kernel 5.2, version 05.29.19; kernel 5.3, version 05.38.19; kernel 5.4, version 05.46.19; kernel 5.5, version 05.54.19; kernel 5.6, version 05.61.19.

A flaw was found in util-linux. Improper hostname canonicalization in the login(1) utility, when invoked with the -h option, can modify the supplied remote hostname before setting PAMRHOST. A remote attacker could exploit this by providing a specially crafted hostname, potentially bypassing host-based Pluggable Authentication Modules (PAM) access control rules that rely on fully qualified domain names. This could lead to unauthorized access.

The sgbuildindirect function in drivers/scsi/sg.c in Linux kernel 2.6.28-rc1 through 2.6.31-rc8 uses an incorrect variable when accessing an array, which allows local users to cause a denial of service (kernel OOPS and NULL pointer dereference), as demonstrated by using xcdroast to duplicate a CD. NOTE: this is only exploitable by users who can open the cdrom device.

The parsedosextended 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 partition table with an extended partition boot record at zero offset.

Integer overflow in the hrtimerforward function (hrtimer.c) in Linux kernel 2.6.21-rc4, when running on 64-bit systems, allows local users to cause a denial of service (infinite loop) via a timer with a large expiry value, which causes the timer to always be expired.

Last updated 31 August 2026

A security issue was fixed in kernel 4.4-rc4 resolving the bypassing of filesystem permission checks in overlayfs during the initial copyup.

Upstream patch:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=acff81ec2c79492b180fade3c2894425cd35a545

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. (Specifically escape sequences received from stdin are blocked but escape sequences received from argv are not blocked.) There may be plausible scenarios where this leads to account takeover.

(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 option or (2) attempting to mount a non-existent device, which generates different error messages depending on whether the directory exists.

A flaw was reported in colcrt:

When running colcrt with a big input it crashes because of a global-buffer-overflow caused by a global variable 'page' defined in 'text-utils/colcrt.c:73:9

It is unclear whether this can be used to execute code on the system.

Proposed patches:

https://github.com/kerolasa/lelux-utiliteetit/commit/70e3fcf293c1827a2655a86584ab13075124a8a8 https://github.com/kerolasa/lelux-utiliteetit/commit/d883d64d96ab9bef510745d064a351145b9babec