A vulnerability in Google Cloud Platform's guest-oslogin versions between 20190304 and 20200507 allows a user that is only granted the role "roles/compute.osLogin" to escalate privileges to root. Using their membership to the "adm" group, users with this role are able to read the DHCP XID from the systemd journal. Using the DHCP XID, it is then possible to set the IP address and hostname of the instance to any value, which is then stored in /etc/hosts. An attacker can then point metadata.google.internal to an arbitrary IP address and impersonate the GCE metadata server which make it is possible to instruct the OS Login PAM module to grant administrative privileges. All images created after 2020-May-07 (20200507) are fixed, and if you cannot update, we recommend you edit /etc/group/security.conf and remove the "adm" user from the OS Login entry.

An issue was discovered in Icinga2 before v2.12.0-rc1. The prepare-dirs script (run as part of the icinga2 systemd service) executes chmod 2750 /run/icinga2/cmd. /run/icinga2 is under control of an unprivileged user by default. If /run/icinga2/cmd is a symlink, then it will by followed and arbitrary files can be changed to mode 2750 by the unprivileged icinga2 user.

systemd through v245 mishandles numerical usernames such as ones composed of decimal digits or 0x followed by hex digits, as demonstrated by use of root privileges when privileges of the 0x0 user account were intended. NOTE: this issue exists because of an incomplete fix for CVE-2017-1000082.

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.

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

An issue was discovered in Microvirt MEmu all versions prior to 7.0.2. A guest Android operating system inside the MEmu emulator contains a /system/bin/systemd binary that is run with root privileges on startup (this is unrelated to Red Hat's systemd init program, and is a closed-source proprietary tool that seems to be developed by Microvirt). This program opens TCP port 21509, presumably to receive installation-related commands from the host OS. Because everything after the installer:uninstall command is concatenated directly into a system() call, it is possible to execute arbitrary commands by supplying shell metacharacters.

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 239 through 245 accepts any certificate signed by a trusted certificate authority for DNS Over TLS. Server Name Indication (SNI) is not sent, and there is no hostname validation with the GnuTLS backend. NOTE: This has been disputed by the developer as not a vulnerability since hostname validation does not have anything to do with this issue (i.e. there is no hostname to be sent)

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.

A vulnerability was found in libvirt >= 4.1.0 in the virtlockd-admin.socket and virtlogd-admin.socket systemd units. A missing SocketMode configuration parameter allows any user on the host to connect using virtlockd-admin-sock or virtlogd-admin-sock and perform administrative tasks against the virtlockd and virtlogd daemons.

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.

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.

In systemd before v242-rc4, it was discovered that pam_systemd does not properly sanitize the environment before using the XDG_SEAT variable. It is possible for an attacker, in some particular configurations, to set a XDG_SEAT environment variable which allows for commands to be checked against polkit policies using the "allow_active" element rather than "allow_any".

A vulnerability was discovered in vdsm, version 4.19 through 4.30.3 and 4.30.5 through 4.30.8. The systemd_run function exposed to the vdsm system user could be abused to execute arbitrary commands as root.

An issue was discovered in sd-bus in systemd 239. bus_process_object() in libsystemd/sd-bus/bus-objects.c allocates a variable-length stack buffer for temporarily storing the object path of incoming D-Bus messages. An unprivileged local user can exploit this by sending a specially crafted message to PID1, causing the stack pointer to jump over the stack guard pages into an unmapped memory region and trigger a denial of service (systemd PID1 crash and kernel panic).

A memory leak was discovered in the backport of fixes for CVE-2018-16864 in Red Hat Enterprise Linux. Function dispatch_message_real() in journald-server.c does not free the memory allocated by set_iovec_field_free() to store the `_CMDLINE=` entry. A local attacker may use this flaw to make systemd-journald crash. This issue only affects versions shipped with Red Hat Enterprise since v219-62.2.

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.

An allocation of memory without limits, that could result in the stack clashing with another memory region, was discovered in systemd-journald when many entries are sent to the journal socket. A local attacker, or a remote one if systemd-journal-remote is used, may use this flaw to crash systemd-journald or execute code with journald privileges. Versions through v240 are vulnerable.

An allocation of memory without limits, that could result in the stack clashing with another memory region, was discovered in systemd-journald when a program with long command line arguments calls syslog. A local attacker may use this flaw to crash systemd-journald or escalate his privileges. Versions through v240 are vulnerable.