Vulnerability-Lookup

GHSA-W55R-JJXW-GXRX

Vulnerability from github – Published: 2026-07-06 21:30 – Updated: 2026-07-08 15:31

Details

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

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-11405"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-06T20:16:29Z",
    "severity": "CRITICAL"
  },
  "details": "The web server binary /bin/httpd contains a hidden backdoor authentication mechanism in the login() function at 004c88b8.\n\n- The function contains a normal authentication path using MD5/hash-based password verification (prod_encode64/PasswordToMd5/check_rand_key).\n- After normal authentication fails, it calls GetValue(\"sys.rzadmin.password\") to read a backdoor password from the device configuration.\n- It performs a direct strcmp() comparison (plaintext, not hashed) between the config value and the user-supplied password.\n\nA successful match grants role=2 (admin-level access) and creates a valid session. The rzadmin username is never checked \u2014 any username works with the backdoor",
  "id": "GHSA-w55r-jjxw-gxrx",
  "modified": "2026-07-08T15:31:49Z",
  "published": "2026-07-06T21:30:39Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-11405"
    },
    {
      "type": "WEB",
      "url": "https://cwe.mitre.org/data/definitions/912.html"
    },
    {
      "type": "WEB",
      "url": "https://kb.cert.org/vuls/id/213560"
    },
    {
      "type": "WEB",
      "url": "https://www.kb.cert.org/vuls/id/213560"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-11405 (GCVE-0-2026-11405)

Vulnerability from cvelistv5 – Published: 2026-07-06 19:17 – Updated: 2026-07-08 13:40

Title

Hidden backdoor authentication mechanism in multiple versions of Tenda firmware allows admin access to web management interface

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

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-912 - Hidden Functionality

Assigner

certcc

References

3 references

URL	Tags
https://cwe.mitre.org/data/definitions/912.html
https://kb.cert.org/vuls/id/213560
https://www.kb.cert.org/vuls/id/213560

Impacted products

5 products

Vendor	Product	Version
Tenda	firmware	Affected: US_AC6V2.0RTL_V15.03.06.51_multi_T
Tenda	firmware	Affected: US_AC5V1.0RTL_V15.03.06.48_multi_TDE01
Tenda	firmware	Affected: US_AC10V1.0re_V15.03.06.46_multi_TDE01
Tenda	firmware	Affected: US_W15EV1.0br_V15.11.0.5(1068_1567_841)_EN_TDE
Tenda	firmware	Affected: US_FH1201V1.0BR_V1.2.0.14(408)_EN_TD

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JSON

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{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-07-06T20:37:55.739Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "https://www.kb.cert.org/vuls/id/213560"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.8,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "HIGH",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-11405",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-08T03:56:43.961536Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-08T13:40:24.471Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "firmware",
          "vendor": "Tenda",
          "versions": [
            {
              "status": "affected",
              "version": "US_AC6V2.0RTL_V15.03.06.51_multi_T"
            }
          ]
        },
        {
          "product": "firmware",
          "vendor": "Tenda",
          "versions": [
            {
              "status": "affected",
              "version": "US_AC5V1.0RTL_V15.03.06.48_multi_TDE01"
            }
          ]
        },
        {
          "product": "firmware",
          "vendor": "Tenda",
          "versions": [
            {
              "status": "affected",
              "version": "US_AC10V1.0re_V15.03.06.46_multi_TDE01"
            }
          ]
        },
        {
          "product": "firmware",
          "vendor": "Tenda",
          "versions": [
            {
              "status": "affected",
              "version": "US_W15EV1.0br_V15.11.0.5(1068_1567_841)_EN_TDE"
            }
          ]
        },
        {
          "product": "firmware",
          "vendor": "Tenda",
          "versions": [
            {
              "status": "affected",
              "version": "US_FH1201V1.0BR_V1.2.0.14(408)_EN_TD"
            }
          ]
        }
      ],
      "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 \u2014 any username works with the backdoor"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-912: Hidden Functionality",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-06T19:24:17.280Z",
        "orgId": "37e5125f-f79b-445b-8fad-9564f167944b",
        "shortName": "certcc"
      },
      "references": [
        {
          "url": "https://cwe.mitre.org/data/definitions/912.html"
        },
        {
          "url": "https://kb.cert.org/vuls/id/213560"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Hidden backdoor authentication mechanism in multiple versions of Tenda firmware allows admin access to web management interface",
      "x_generator": {
        "engine": "VINCE 3.0.43",
        "env": "prod",
        "origin": "https://cveawg.mitre.org/api/cve/CVE-2026-11405"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "37e5125f-f79b-445b-8fad-9564f167944b",
    "assignerShortName": "certcc",
    "cveId": "CVE-2026-11405",
    "datePublished": "2026-07-06T19:17:07.891Z",
    "dateReserved": "2026-06-05T18:12:15.445Z",
    "dateUpdated": "2026-07-08T13:40:24.471Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-W55R-JJXW-GXRX

CVE-2026-11405 (GCVE-0-2026-11405)

Tags

Sightings

Nomenclature