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CVE-2026-54411

Estado: AplazadaMedia (6.9)—

Linux-PAM through 1.7.2 contains an observable timing discrepancy (CWE-208) in the pam_userdb module's plaintext-password comparison path in modules/pam_userdb/pam_userdb.c that allows a local or network-adjacent attacker able to repeatedly drive authentication through a calling service to recover the plaintext password of a target account by measuring response-timing differences.

CVSS

Probabilidad de explotación (EPSS)

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).

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux-pam — Linux-pamAI

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-54411",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-54411",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-06-15T16:59:25.401303Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.9,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 2.2
      }
    ],
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
          "baseScore": 6.9,
          "Automatable": "NO",
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "valueDensity": "DIFFUSE",
          "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:X/V:D/RE:X/U:X",
          "exploitMaturity": "PROOF_OF_CONCEPT",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "NONE",
          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
        }
      }
    ]
  },
  "affected": [
    {
      "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
      "affectedData": [
        {
          "repo": "https://github.com/linux-pam/linux-pam",
          "vendor": "Linux-PAM",
          "modules": [
            "pam_userdb"
          ],
          "product": "Linux-PAM",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "versionType": "semver",
              "lessThanOrEqual": "1.7.2"
            }
          ],
          "programFiles": [
            "modules/pam_userdb/pam_userdb.c"
          ],
          "collectionURL": "https://github.com/linux-pam/linux-pam",
          "defaultStatus": "unknown"
        }
      ]
    }
  ],
  "published": "2026-06-14T18:17:20.587",
  "references": [
    {
      "url": "https://cwe.mitre.org/data/definitions/208.html",
      "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"
    },
    {
      "url": "https://github.com/linux-pam/linux-pam",
      "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"
    },
    {
      "url": "https://github.com/linux-pam/linux-pam/blob/master/libpam/include/pam_inline.h",
      "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"
    },
    {
      "url": "https://github.com/linux-pam/linux-pam/blob/master/modules/pam_userdb/pam_userdb.c#L327",
      "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c",
      "description": [
        {
          "lang": "en",
          "value": "CWE-208"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Linux-PAM through 1.7.2 contains an observable timing discrepancy (CWE-208) in the pam_userdb module's plaintext-password comparison path in modules/pam_userdb/pam_userdb.c that allows a local or network-adjacent attacker able to repeatedly drive authentication through a calling service to recover the plaintext password of a target account by measuring response-timing differences."
    },
    {
      "lang": "es",
      "value": "Linux-PAM hasta 1.7.2 contiene una discrepancia de tiempo observable (CWE-208) en la ruta de comparación de contraseñas en texto plano del módulo pam_userdb en modules/pam_userdb/pam_userdb.c que permite a un atacante local o adyacente a la red, capaz de impulsar repetidamente la autenticación a través de un servicio llamante, recuperar la contraseña en texto plano de una cuenta objetivo midiendo las diferencias de tiempo de respuesta. La comparación utiliza strncmp() (o strncasecmp() cuando PAM_ICASE_ARG está configurado) precedida por una verificación de igualdad de longitud, por lo que el tiempo para rechazar un candidato depende del índice del primer byte diferente y de si la longitud del candidato coincide con la contraseña almacenada, filtrando la longitud de la contraseña y los bytes de prefijo individuales. La ruta vulnerable se alcanza cuando el administrador configura pam_userdb con crypt=none, con un método crypt no reconocido, o sin un argumento crypt=, lo que hace que el módulo almacene y compare credenciales en texto plano."
    }
  ],
  "lastModified": "2026-08-10T12:17:17.103",
  "sourceIdentifier": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"
}