Hidden backdoor authentication mechanism in multiple versions of Tenda firmware allows admin access to web management interface
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- 1 proof of concept on GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: total
Summary
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
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: total
- Record last updated
Affected 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