Cisco Security Advisory – A vulnerability in Cisco Prime Collaboration Assurance (PCA) Software could allow an unauthenticated, remote attacker to log in to the system shell with the default cmuser user account and access the shell with a limited set of permissions. The vulnerability is due to an undocumented account that has a default and static password. This account is created during installation and cannot be changed or deleted without impacting the functionality of the system. The first time this account is used the system will request that the user change the default password. An attacker could exploit this vulnerability by remotely connecting to the affected system via SSH by using the undocumented account. Successful exploitation could allow the attacker to access the system with the privileges of the cmuser user. This vulnerability allows the attacker to: access some sensitive data, such as the password file, system logs, and Cisco PCA database information; modify some data; run some internal executables; and potentially make the system unstable or inaccessible. Cisco has released software updates that address this vulnerability. Workarounds are available.