An issue was discovered in dbus >= 1.3.0 before 1.12.18. The DBusServer in libdbus, as used in dbus-daemon, leaks file descriptors when a message exceeds the per-message file descriptor limit. A local attacker with access to the D-Bus system bus or another system service's private AF_UNIX socket could use this to make the system service reach its file descriptor limit, denying service to subsequent D-Bus clients.
https://usn.ubuntu.com/4398-2/
https://usn.ubuntu.com/4398-1/
https://securitylab.github.com/advisories/GHSL-2020-057-DBus-DoS-file-descriptor-leak
https://security.gentoo.org/glsa/202007-46
https://gitlab.freedesktop.org/dbus/dbus/-/tags/dbus-1.13.16
https://gitlab.freedesktop.org/dbus/dbus/-/tags/dbus-1.12.18
https://gitlab.freedesktop.org/dbus/dbus/-/tags/dbus-1.10.30
https://gitlab.freedesktop.org/dbus/dbus/-/issues/294
http://www.openwall.com/lists/oss-security/2020/06/04/3
http://packetstormsecurity.com/files/172840/D-Bus-File-Descriptor-Leak-Denial-Of-Service.html