Incorrect command-line parameter validation in the Xorg X server can lead to privilege elevation and/or arbitrary files overwrite, when the X server is installed with the setuid bit set and unprivileged users have the ability to log in to the system via physical console. The -modulepath argument can be used to specify an insecure path to modules that are going to be loaded in the X server, allowing to execute unprivileged code in the privileged process. The -logfile argument can be used to overwrite arbitrary files in the file system, due to incorrect checks in the parsing of the option.
Incorrect command-line parameter validation in the Xorg X server can lead to privilege elevation and/or arbitrary files overwrite, when the X server is installed with the setuid bit set and unprivileged users have the ability to log in to the system via physical console. The -modulepath argument can be used to specify an insecure path to modules that are going to be loaded in the X server, allowing to execute unprivileged code in the privileged process. The -logfile argument can be used to overwrite arbitrary files in the file system, due to incorrect checks in the parsing of the option.
https://gitlab.freedesktop.org/xorg/xserver/commit/50c0cf885a6e91c0ea71fb49fa8f1b7c86fe330e https://gitlab.freedesktop.org/xorg/xserver/commit/032b1d79b7 https://www.openwall.com/lists/oss-security/2018/10/25/1