A privilege escalation vulnerability in the Secure Shell (SSH) subsystem in the StarOS operating system for Cisco ASR 5000 Series, ASR 5500 Series, ASR 5700 Series devices, and Cisco Virtualized Packet Core could allow an authenticated, remote attacker to gain unrestricted, root shell access. The vulnerability is due to missing input validation of parameters passed during SSH or SFTP login. An attacker could exploit this vulnerability by providing crafted user input to the SSH or SFTP command-line interface (CLI) during SSH or SFTP login. An exploit could allow an authenticated attacker to gain root privileges access on the router. Note: Only traffic directed to the affected system can be used to exploit this vulnerability. This vulnerability can be triggered via both IPv4 and IPv6 traffic. An established TCP connection toward port 22, the SSH default port, is needed to perform the attack. The attacker must have valid credentials to login to the system via SSH or SFTP. The following p…

The SSH implementation in Cisco StarOS before 19.3.M0.62771 and 20.x before 20.0.M0.62768 on ASR 5000 devices mishandles a multi-user public-key authentication configuration, which allows remote authenticated users to gain privileges by establishing a connection from an endpoint that was previously used for an administrator's connection, aka Bug ID CSCux22492.