CVE-2025-40923
Plack-Middleware-Session before version 0.35 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.
Predicable session ids could allow an attacker to gain access to systems.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- Puntuación base: 7.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.34%
- Percentil entre todas las CVEs puntuadas: 25
- 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.
- Explotación
T1190Exploit Public-Facing Applicationinitial access75 % - Impacto principal
T1078.001Default Accountsstealth · persistence · privilege escalation · initial access70 % - Impacto secundario
T1552.007Container APIcredential access65 %
Red sin privilegios (AV:N/PR:N) genera T1190. Sesiones predecibles permiten falsificar o robar cookies de sesión (T1078.001) y exponer datos de sesión en memoria (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
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-338, CWE-340
Referencias
- https://github.com/plack/Plack-Middleware-Session/commit/1fbfbb355e34e7f4b3906f66cf958cedadd2b9be.patch
- https://github.com/plack/Plack-Middleware-Session/pull/52
- https://metacpan.org/release/MIYAGAWA/Plack-Middleware-Session-0.34/source/lib/Plack/Session/State.pm#L22
- https://security.metacpan.org/docs/guides/random-data-for-security.html
- http://www.openwall.com/lists/oss-security/2025/07/16/4
JSON original (NVD)
Mostrar
{
"id": "CVE-2025-40923",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2025-40923",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2025-07-16T20:47:49.157521Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.3,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"integrityImpact": "LOW",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "LOW",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
},
"impactScore": 3.4,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
"affectedData": [
{
"repo": "https://github.com/plack/Plack-Middleware-Session",
"vendor": "MIYAGAWA",
"product": "Plack::Middleware::Session",
"versions": [
{
"status": "affected",
"version": "0.01",
"lessThan": "0.35",
"versionType": "custom"
}
],
"packageName": "Plack-Middleware-Session",
"programFiles": [
"lib/Plack/Session/State.pm"
],
"collectionURL": "https://cpan.org/modules",
"defaultStatus": "unaffected"
}
]
}
],
"published": "2025-07-16T13:15:23.997",
"references": [
{
"url": "https://github.com/plack/Plack-Middleware-Session/commit/1fbfbb355e34e7f4b3906f66cf958cedadd2b9be.patch",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
},
{
"url": "https://github.com/plack/Plack-Middleware-Session/pull/52",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
},
{
"url": "https://metacpan.org/release/MIYAGAWA/Plack-Middleware-Session-0.34/source/lib/Plack/Session/State.pm#L22",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
},
{
"url": "https://security.metacpan.org/docs/guides/random-data-for-security.html",
"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
},
{
"url": "http://www.openwall.com/lists/oss-security/2025/07/16/4",
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Deferred",
"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 before version 0.35 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\nPredicable session ids could allow an attacker to gain access to systems."
},
{
"lang": "es",
"value": "Las versiones anteriores a la 0.35 de Plack-Middleware-Session para Perl generan identificadores de sesión de forma insegura. El generador de identificadores de sesión predeterminado devuelve un hash SHA-1 con la función rand integrada, la fecha y hora y el PID. El PID se obtendrá de un pequeño conjunto de números, y la fecha y hora pueden ser adivinadas si no se filtran del encabezado HTTP Date. La función rand integrada no es adecuada para uso criptográfico. Los identificadores de sesión predecibles podrían permitir que un atacante acceda a los sistemas. "
}
],
"lastModified": "2026-06-17T09:22:17.947",
"sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
}