CVE-2025-40926

Estado: ModificadaCrítica (9.8)—

Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely.

The default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.

Predictable session ids could allow an attacker to gain access to systems.

Plack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923.

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: 0.45%
Percentil entre todas las CVEs puntuadas: 37
Fecha de la puntuación: 6/10/2026

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 access85 %
Impacto principalT1078 Valid Accountsstealth · persistence · privilege escalation · initial access80 %

AV:N/PR:N/UI:N permite explotación remota sin privilegios (T1190). Session IDs predecibles permiten acceso no autorizado a cuentas (T1078) y exposición de credenciales/tokens de sesión (T1552.007).

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

Privileged Account Management Application Developer Guidance Active Directory Configuration Vulnerability Scanning User Training User Account Management

Tecnologías afectadas (1)

Kazeburo — Plack\

CWE

CWE-338, CWE-340

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2025-40926",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2025-40926",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-03-05T16:28:14.069463Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "cvssData": {
          "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"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "affectedData": [
        {
          "repo": "https://github.com/kazeburo/Plack-Middleware-Session-Simple",
          "vendor": "KAZEBURO",
          "product": "Plack::Middleware::Session::Simple",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "0.05",
              "versionType": "custom"
            }
          ],
          "packageName": "Plack-Middleware-Session-Simple",
          "programFiles": [
            "lib/Plack/Middleware/Session/Simple.pm"
          ],
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "programRoutines": [
            {
              "name": "Plack::Middleware::Session::Simple::sid_generator"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-03-05T02:16:39.790",
  "references": [
    {
      "url": "https://github.com/kazeburo/Plack-Middleware-Session-Simple/commit/760bb358b8f53e52cf415888a4ac858fd99bb24e.patch",
      "tags": [
        "Patch"
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    },
    {
      "url": "https://github.com/kazeburo/Plack-Middleware-Session-Simple/pull/4",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    },
    {
      "url": "https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.04/source/lib/Plack/Middleware/Session/Simple.pm#L43",
      "tags": [
        "Issue Tracking",
        "Product"
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    },
    {
      "url": "https://metacpan.org/release/KAZEBURO/Plack-Middleware-Session-Simple-0.05/changes",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    },
    {
      "url": "https://security.metacpan.org/docs/guides/random-data-for-security.html",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    },
    {
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-40923",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "description": [
        {
          "lang": "en",
          "value": "CWE-338"
        },
        {
          "lang": "en",
          "value": "CWE-340"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Plack::Middleware::Session::Simple versions before 0.05 for Perl generates session ids insecurely.\n\nThe default session id generator returns a SHA-1 hash seeded with the built-in rand function, the epoch time, and the PID. The PID will come from a small set of numbers, and the epoch time may be guessed, if it is not leaked from the HTTP Date header. The built-in rand function is unsuitable for cryptographic usage.\n\nPredictable session ids could allow an attacker to gain access to systems.\n\nPlack::Middleware::Session::Simple is intended to be compatible with Plack::Middleware::Session, which had a similar security issue CVE-2025-40923."
    },
    {
      "lang": "es",
      "value": "Las versiones de Plack::Middleware::Session::Simple hasta la 0.04 para Perl generan identificadores de sesión de forma insegura.\n\nEl generador predeterminado de identificadores de sesión devuelve un hash SHA-1 inicializado con la función rand incorporada, el tiempo epoch y el PID. El PID provendrá de un pequeño conjunto de números, y el tiempo epoch puede ser adivinado, si no se filtra del encabezado HTTP Date. La función rand incorporada no es adecuada para uso criptográfico.\n\nLos identificadores de sesión predecibles podrían permitir a un atacante obtener acceso a los sistemas.\n\nPlack::Middleware::Session::Simple está diseñado para ser compatible con Plack::Middleware::Session, que tuvo un problema de seguridad similar CVE-2025-40923."
    }
  ],
  "lastModified": "2026-06-17T09:22:18.360",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:kazeburo:plack\\:\\:middleware\\:\\:session\\:\\:simple:*:*:*:*:*:perl:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B99A5199-295A-487A-95D0-2DDF94AFDE71",
              "versionEndExcluding": "0.05"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
}