CVE-2026-11405

Estado: AplazadaCrítica (9.8)—

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

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 9.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.77%
Percentil entre todas las CVEs puntuadas: 54
Fecha de la puntuación: 5/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

ExplotaciónT1190 Exploit Public-Facing Applicationinitial access95 %
Impacto principalT1078.001 Default Accountsstealth · persistence · privilege escalation · initial access90 %

Vulnerabilidad de backdoor en servidor web expuesto (AV:N, PR:N): autenticación bypass mediante strcmp() plaintext permite acceso sin privilegios a rol admin (T1078.001) y ejecución de comandos posteriores (T1059).

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Vulnerability Scanning Privileged Account Management Password Policies Network Segmentation Multi-factor Authentication Limit Access to Resource Over Network

Referencias

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  "id": "CVE-2026-11405",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-11405",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-07-08T03:56:43.961536Z"
        }
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    "cvssMetricV31": [
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          "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"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 3.9
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  },
  "affected": [
    {
      "source": "cret@cert.org",
      "affectedData": [
        {
          "vendor": "Tenda",
          "product": "firmware",
          "versions": [
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              "status": "affected",
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  "published": "2026-07-06T20:16:29.450",
  "references": [
    {
      "url": "https://cwe.mitre.org/data/definitions/912.html",
      "source": "cret@cert.org"
    },
    {
      "url": "https://kb.cert.org/vuls/id/213560",
      "source": "cret@cert.org"
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    {
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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  "vulnStatus": "Deferred",
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    {
      "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"
    }
  ],
  "lastModified": "2026-07-08T14:16:54.773",
  "sourceIdentifier": "cret@cert.org"
}