{"id":"CVE-2026-11405","state":"PUBLISHED","title":"Hidden backdoor authentication mechanism in multiple versions of Tenda firmware allows admin access to web management interface","description":"The web server binary /bin/httpd contains a hidden backdoor authentication mechanism in the login() function at 004c88b8.\r\n\r\n- The function contains a normal authentication path using MD5/hash-based password verification (prod_encode64/PasswordToMd5/check_rand_key).\r\n- After normal authentication fails, it calls GetValue(\"sys.rzadmin.password\") to read a backdoor password from the device configuration.\r\n- It performs a direct strcmp() comparison (plaintext, not hashed) between the config value and the user-supplied password.\r\n\r\nA 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","publishedAt":"2026-07-06T19:17:07.891Z","updatedAt":"2026-07-08T13:40:24.471Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"CISA-ADP"},"assigner":"certcc","products":["Tenda firmware"],"affected":[{"vendor":"Tenda","product":"firmware","versions":[{"version":"US_AC6V2.0RTL_V15.03.06.51_multi_T","status":"affected"}]},{"vendor":"Tenda","product":"firmware","versions":[{"version":"US_AC5V1.0RTL_V15.03.06.48_multi_TDE01","status":"affected"}]},{"vendor":"Tenda","product":"firmware","versions":[{"version":"US_AC10V1.0re_V15.03.06.46_multi_TDE01","status":"affected"}]},{"vendor":"Tenda","product":"firmware","versions":[{"version":"US_W15EV1.0br_V15.11.0.5(1068_1567_841)_EN_TDE","status":"affected"}]},{"vendor":"Tenda","product":"firmware","versions":[{"version":"US_FH1201V1.0BR_V1.2.0.14(408)_EN_TD","status":"affected"}]}],"references":["https://cwe.mitre.org/data/definitions/912.html","https://kb.cert.org/vuls/id/213560","https://www.kb.cert.org/vuls/id/213560"],"weaknesses":[],"ingestedAt":"2026-10-29T20:10:52.580Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/11xxx/CVE-2026-11405.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-11405","state":"PUBLISHED","datePublished":"2026-07-06T19:17:07.891Z","dateUpdated":"2026-07-08T13:40:24.471Z","assignerShortName":"certcc","assignerOrgId":"37e5125f-f79b-445b-8fad-9564f167944b","dateReserved":"2026-06-05T18:12:15.445Z"},"containers":{"cna":{"title":"Hidden backdoor authentication mechanism in multiple versions of Tenda firmware allows admin access to web management interface","descriptions":[{"lang":"en","value":"The web server binary /bin/httpd contains a hidden backdoor authentication mechanism in the login() function at 004c88b8.\r\n\r\n- The function contains a normal authentication path using MD5/hash-based password verification (prod_encode64/PasswordToMd5/check_rand_key).\r\n- After normal authentication fails, it calls GetValue(\"sys.rzadmin.password\") to read a backdoor password from the device configuration.\r\n- It performs a direct strcmp() comparison (plaintext, not hashed) between the config value and the user-supplied password.\r\n\r\nA 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"}],"affected":[{"vendor":"Tenda","product":"firmware","versions":[{"version":"US_AC6V2.0RTL_V15.03.06.51_multi_T","status":"affected"}]},{"vendor":"Tenda","product":"firmware","versions":[{"version":"US_AC5V1.0RTL_V15.03.06.48_multi_TDE01","status":"affected"}]},{"vendor":"Tenda","product":"firmware","versions":[{"version":"US_AC10V1.0re_V15.03.06.46_multi_TDE01","status":"affected"}]},{"vendor":"Tenda","product":"firmware","versions":[{"version":"US_W15EV1.0br_V15.11.0.5(1068_1567_841)_EN_TDE","status":"affected"}]},{"vendor":"Tenda","product":"firmware","versions":[{"version":"US_FH1201V1.0BR_V1.2.0.14(408)_EN_TD","status":"affected"}]}],"references":[{"url":"https://cwe.mitre.org/data/definitions/912.html"},{"url":"https://kb.cert.org/vuls/id/213560"}],"problemTypes":[{"descriptions":[{"lang":"en","description":"CWE-912: Hidden Functionality"}]}],"providerMetadata":{"shortName":"certcc","orgId":"37e5125f-f79b-445b-8fad-9564f167944b","dateUpdated":"2026-07-06T19:24:17.280Z"},"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"VINCE 3.0.43","env":"prod","origin":"https://cveawg.mitre.org/api/cve/CVE-2026-11405"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://www.kb.cert.org/vuls/id/213560"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-07-06T20:37:55.739Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":9.8,"attackVector":"NETWORK","baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-07-08T03:56:43.961536Z","id":"CVE-2026-11405","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-08T13:40:24.471Z"}}]}}}