systemd Project systemd

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 parse_elf_object 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.

systemd: Local unprivileged user can trigger an assert

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.

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."

An issue was discovered in systemd 253. An attacker can modify a sealed log file such that, in some views, not all existing and sealed log messages are displayed. NOTE: the vendor reportedly sent "a reply denying that any of the finding was a security vulnerability."

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."

An issue was discovered in button_open in login/logind-button.c in systemd before 243. When executing the udevadm trigger command, a memory leak may occur.

systemd, when updating file permissions, allows local users to change the permissions and SELinux security contexts for arbitrary files via a symlink attack on unspecified files.

Systemd-coredump: race condition that allows a local attacker to crash a suid program and gain read access to the resulting core dump

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.

In systemd 240, bus_open_system_watch_bind_with_description in shared/bus-util.c (as used by systemd-resolved to connect to the system D-Bus instance), calls sd_bus_set_trusted, which disables access controls for incoming D-Bus messages. An unprivileged user can exploit this by executing D-Bus methods that should be restricted to privileged users, in order to change the system's DNS resolver settings.

systemd 242 changes the VT1 mode upon a logout, which allows attackers to read cleartext passwords in certain circumstances, such as watching a shutdown, or using Ctrl-Alt-F1 and Ctrl-Alt-F2. This occurs because the KDGKBMODE (aka current keyboard mode) check is mishandled.

An out of bounds read was discovered in systemd-journald in the way it parses log messages that terminate with a colon ':'. A local attacker can use this flaw to disclose process memory data. Versions from v221 to v239 are vulnerable.

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.

journald in systemd, when the origin of native messages is set to file, allows local users to cause a denial of service (logging service blocking) via a crafted file descriptor.