Deepin lastore-daemon Privilege Escalation via Unsigned .deb Installation

A local privilege escalation vulnerability exists in lastore-daemon, the system package manager daemon used in Deepin Linux (developed by Wuhan Deepin Technology Co., Ltd.). In versions 0.9.53-1 (Deepin 15.5) and 0.9.66-1 (Deepin 15.7), the D-Bus configuration permits any user in the sudo group to invoke the InstallPackage method without password authentication. By default, the first user created on Deepin is in the sudo group. An attacker with shell access can craft a .deb package containing a malicious post-install script and use dbus-send to install it via lastore-daemon, resulting in arbitrary code execution as root.