Insecure Permissions vulnerability in Tenda CP3 Pro Firmware V22.5.4.93 allows the telnet service (telnetd) by default at boot via the initialization script /etc/init.d/eth.sh. This allows remote attackers to connect to the device s shell over the network, potentially without authentication if default or weak credentials are present
The product uses weak credentials (such as a default key or hard-coded password) that can be calculated, derived, reused, or guessed by an attacker.
By design, authentication protocols try to ensure that attackers must perform brute force attacks if they do not know the credentials such as a key or password. However, when these credentials are easily predictable or even fixed (as with default or hard-coded passwords and keys), then the attacker can defeat the mechanism without relying on brute force. Credentials may be weak for different reasons, such as:
Even if a new, unique credential is intended to be generated for each product installation, if the generation is predictable, then that may also simplify guessing attacks.