DLA-4166-1

xrdp is an open source remote desktop protocol (RDP) server. In versions prior to 0.9.23 improper handling of session establishment errors allows bypassing OS-level session restrictions. The `auth_start_session` function can return non-zero (1) value on, e.g., PAM error which may result in in session restrictions such as max concurrent sessions per user by PAM (ex ./etc/security/limits.conf) to be bypassed. Users (administrators) don't use restrictions by PAM are not affected. This issue has been addressed in release version 0.9.23. Users are advised to upgrade. There are no known workarounds for this issue.

xrdp is an open source remote desktop protocol server. Access to the font glyphs in xrdp_painter.c is not bounds-checked . Since some of this data is controllable by the user, this can result in an out-of-bounds read within the xrdp executable. The vulnerability allows an out-of-bounds read within a potentially privileged process. On non-Debian platforms, xrdp tends to run as root. Potentially an out-of-bounds write can follow the out-of-bounds read. There is no denial-of-service impact, providing xrdp is running in forking mode. This issue has been addressed in release 0.9.23.1. Users are advised to upgrade. There are no known workarounds for this vulnerability.

xrdp is an open source RDP server. xrdp versions prior to 0.10.0 have a vulnerability that allows attackers to make an infinite number of login attempts. The number of max login attempts is supposed to be limited by a configuration parameter `MaxLoginRetry` in `/etc/xrdp/sesman.ini`. However, this mechanism was not effectively working. As a result, xrdp allows an infinite number of login attempts.