xrdp is an open source remote desktop protocol (RDP) server. In affected versions an integer underflow leading to a heap overflow in the sesman server allows any unauthenticated attacker which is able to locally access a sesman server to execute code as root. This vulnerability has been patched in version 0.9.18.1 and above. Users are advised to upgrade. There are no known workarounds.

xrdp 0.9.1 calls the PAM function auth_start_session() in an incorrect location, leading to PAM session modules not being properly initialized, with a potential consequence of incorrect configurations or elevation of privileges, aka a pam_limits.so bypass.