A security flaw has been discovered in Tenda AC20 16.03.08.12. Affected by this vulnerability is an unknown functionality of the file /etc_ro/shadow. The manipulation leads to hard-coded credentials. It is possible to launch the attack on the local host. The complexity of an attack is rather high. The exploitation appears to be difficult. The exploit has been disclosed to the public and may be used.
Weakness
The product contains a hard-coded password, which it uses for its own inbound authentication or for outbound communication to external components.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Ac20_firmware |
Tenda |
16.03.08.12 (including) |
16.03.08.12 (including) |
Extended Description
There are two main variations of a hard-coded password:
Potential Mitigations
- For inbound authentication: apply strong one-way hashes to your passwords and store those hashes in a configuration file or database with appropriate access control. That way, theft of the file/database still requires the attacker to try to crack the password. When receiving an incoming password during authentication, take the hash of the password and compare it to the hash that you have saved.
- Use randomly assigned salts for each separate hash that you generate. This increases the amount of computation that an attacker needs to conduct a brute-force attack, possibly limiting the effectiveness of the rainbow table method.
- For front-end to back-end connections: Three solutions are possible, although none are complete.
References