In systemd 259, systemd-journald can send ANSI escape sequences to the terminals of arbitrary users when a "logger -p emerg" command is executed, if ForwardToWall=yes is set.

In systemd 260 before 261, a local unprivileged user can trigger an assert via an IPC API call with an array or map that has a null element.

In nspawn in systemd 233 through 259 before 260, an escape-to-host action can occur via a crafted optional config file.

In udev in systemd before 260, local root execution can occur via malicious hardware devices and unsanitized kernel output.

In systemd 259 before 260, there is local privilege escalation in systemd-machined because varlink can be used to reach the root namespace.

In systemd 258 before 260, a local unprivileged user can trigger an assert when a Delegate=yes and User=<unset> unit exists and is running.

A race condidition in systemd-coredump allows a local attacker to crash a SUID program and gain read access to the resulting core dump

A vulnerability was found in systemd-resolved. This issue may allow systemd-resolved to accept records of DNSSEC-signed domains even when they have no signature, allowing man-in-the-middles (or the upstream DNS resolver) to manipulate records.

DISPUTED An issue was discovered in systemd 253. An attacker can truncate a sealed log file and then resume log sealing such that checking the integrity shows no error, despite modifications. NOTE: the vendor reportedly sent "a reply denying that any of the finding was a security vulnerability."

DISPUTED An issue was discovered in systemd 253. An attacker can modify the contents of past events in a sealed log file and then adjust the file such that checking the integrity shows no error, despite modifications. NOTE: the vendor reportedly sent "a reply denying that any of the finding was a security vulnerability."

systemd before 247 does not adequately block local privilege escalation for some Sudo configurations, e.g., plausible sudoers files in which the "systemctl status" command may be executed. Specifically, systemd does not set LESSSECURE to 1, and thus other programs may be launched from the less program. This presents a substantial security risk when running systemctl from Sudo, because less executes as root when the terminal size is too small to show the complete systemctl output.

A vulnerability was found in systemd. This security flaw can cause a local information leak due to systemd-coredump not respecting the fs.suiddumpable kernel setting.

systemd 250 and 251 allows local users to achieve a systemd-coredump deadlock by triggering a crash that has a long backtrace. This occurs in parseelfobject in shared/elf-util.c. The exploitation methodology is to crash a binary calling the same function recursively, and put it in a deeply nested directory to make its backtrace large enough to cause the deadlock. This must be done 16 times when MaxConnections=16 is set for the systemd/units/systemd-coredump.socket file.

An off-by-one Error issue was discovered in Systemd in formattimespan() function of time-util.c. An attacker could supply specific values for time and accuracy that leads to buffer overrun in formattimespan(), leading to a Denial of Service.

A use-after-free vulnerability was found in systemd. This issue occurs due to the onstreamio() function and dnsstreamcomplete() function in 'resolved-dns-stream.c' not incrementing the reference counting for the DnsStream object. Therefore, other functions and callbacks called can dereference the DNSStream object, causing the use-after-free when the reference is still used later.

A flaw was found in systemd. An uncontrolled recursion in systemd-tmpfiles may lead to a denial of service at boot time when too many nested directories are created in /tmp.

A heap use-after-free vulnerability was found in systemd before version v245-rc1, where asynchronous Polkit queries are performed while handling dbus messages. A local unprivileged attacker can abuse this flaw to crash systemd services or potentially execute code and elevate their privileges, by sending specially crafted dbus messages.

It was discovered that a systemd service that uses DynamicUser property can get new privileges through the execution of SUID binaries, which would allow to create binaries owned by the service transient group with the setgid bit set. A local attacker may use this flaw to access resources that will be owned by a potentially different service in the future, when the GID will be recycled.

It was discovered that a systemd service that uses DynamicUser property can create a SUID/SGID binary that would be allowed to run as the transient service UID/GID even after the service is terminated. A local attacker may use this flaw to access resources that will be owned by a potentially different service in the future, when the UID/GID will be recycled.

It was discovered systemd does not correctly check the content of PIDFile files before using it to kill processes. When a service is run from an unprivileged user (e.g. User field set in the service file), a local attacker who is able to write to the PIDFile of the mentioned service may use this flaw to trick systemd into killing other services and/or privileged processes. Versions before v237 are vulnerable.

Last updated 24 July 2024

In systemd prior to 234 a race condition exists between .mount and .automount units such that automount requests from kernel may not be serviced by systemd resulting in kernel holding the mountpoint and any processes that try to use said mount will hang. A race condition like this may lead to denial of service, until mount points are unmounted.

In systemd 223 through 235, a remote DNS server can respond with a custom crafted DNS NSEC resource record to trigger an infinite loop in the dnspacketreadtypewindow() function of the 'systemd-resolved' service and cause a DoS of the affected service.

In systemd through 233, certain sizes passed to dnspacketnew in systemd-resolved can cause it to allocate a buffer that's too small. A malicious DNS server can exploit this via a response with a specially crafted TCP payload to trick systemd-resolved into allocating a buffer that's too small, and subsequently write arbitrary data beyond the end of it.

A flaw in systemd v228 in /src/basic/fs-util.c caused world writable suid files to be created when using the systemd timers features, allowing local attackers to escalate their privileges to root. This is fixed in v229.

systemd 37-1 does not properly handle non-existent services, which causes a denial of service (failure of login procedure).

Sebastian Krahmer of the SUSE Security Team reported that systemd-logind, a part of the systemd service and system manager, did not create certain special files in a secure way. systemd-logind is responsible for managing and tracking user login sessions, and if a user were to log into the X11 desktop, it creates entries in /run/user/[username]/X11, where /run/user/[username] is a user-owned directory. Because systemd-logind does not create the entries in a secure fashion, a malicious user could replace /run/user/[username]/X11 with a symlink to another root-owned directory, such as /etc/pam.d or /etc/cron.d. This would cause a symlink named "display" to be created in the target directory, which is a symlink to a user-owned file (/tmp/.X11-unix/X0). Using further attack vectors and this symlink, the malicious user could obtain a root shell, if he could beat two separate race conditions.

Acknowledgements:

Red Hat would like to thank Sebastian Krahmer of the SUSE Security Team for reporting this issue.