CVE-2026-11405
Description
The web server binary /bin/httpd contains a hidden backdoor authentication mechanism in the login() function at 004c88b8.
- The function contains a normal authentication path using MD5/hash-based password verification (prod_encode64/PasswordToMd5/check_rand_key).
- After normal authentication fails, it calls GetValue("sys.rzadmin.password") to read a backdoor password from the device configuration.
- It performs a direct strcmp() comparison (plaintext, not hashed) between the config value and the user-supplied password.
A successful match grants role=2 (admin-level access) and creates a valid session. The rzadmin username is never checked — any username works with the backdoor
Metadata
Severity & Metrics
No CVSS data available.
Affected products (5)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| Tenda | firmware | — | US_AC6V2.0RTL_V15.03.06.51_multi_T |
| Tenda | firmware | — | US_AC5V1.0RTL_V15.03.06.48_multi_TDE01 |
| Tenda | firmware | — | US_AC10V1.0re_V15.03.06.46_multi_TDE01 |
| Tenda | firmware | — | US_W15EV1.0br_V15.11.0.5(1068_1567_841)_EN_TDE |
| Tenda | firmware | — | US_FH1201V1.0BR_V1.2.0.14(408)_EN_TD |
Weakness (CWE)
| CWE | Source | Description |
|---|---|---|
| — | cna | CWE-912: Hidden Functionality |