Cisco recently released a security update to address two critical vulnerabilities: CVE-2021-34795 which allows attackers to gain access with hard-coded credentials, and CVE-2021-40119 which uses default SSH keys to take over unpatched devices.
The first vulnerability has been found in Cisco Catalyst Passive Optical Network (PON) Series Switches Optical Network Terminal (ONT) and may allow a remote attacker to login to the affected device via a debugging account with a default, static password.”
However, the vulnerability is limited in that it can only be exploited by creating a Telnet session with vulnerable devices. Since Telnet is not enabled by default, the number of targets that a threat actor could attack is therefore limited.
The second vulnerability is caused by the re-use of static SSH keys in Cisco Policy Suite installations, allowing a remote attacker to log in to an affected system as the root user.
Cisco’s new software updates automatically generate new SSH keys during installation to address the vulnerability.
For more information, read the original story in Bleeping Computer.