CVE-2026-34181

Estado: AnalizadaAlta (7.4)—

Issue Summary: The PKCS#12 file processing fails to perform sufficient input validation for files that use Password-Based Message Authentication Code 1 (PBMAC1) integrity mechanism allowing a certificate and private key forgery.

Impact Summary: An attacker impersonating a user can cause a service reading PKCS#12 files to accept forged certificates and private keys with a 1 in 256 probability.

If a service accepting PKCS#12 files is using passwords for authenticating the received files, the attacker can create unencrypted PKCS#12 files that use PBMAC1 authentication that specifies an HMAC key of only one byte, allowing them to craft a file that will be accepted with a 1 in 256 probability.

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That would then cause the service to accept a certificate and private key controlled by the attacker.

The FIPS modules are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Puntuación base: 7.4

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.18%
Percentil entre todas las CVEs puntuadas: 7
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 principalT1556 Modify Authentication Processdefense impairment · persistence · credential access80 %
Impacto secundarioT1078 Valid Accountsstealth · persistence · privilege escalation · initial access75 %

Explotación remota de validación insuficiente en PKCS#12 (CWE-354) sin autenticación previa (PR:N). Impactos: suplantación de identidad mediante certificados/claves falsificadas (T1556) y aceptación de credenciales forjadas (T1078).

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 User Account Management Password Policies Multi-factor Authentication Application Developer Guidance Active Directory Configuration

Tecnologías afectadas (1)

Openssl — Openssl

CWE

CWE-354

Referencias

JSON original (NVD)

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      "value": "Issue Summary: The PKCS#12 file processing fails to perform sufficient input\nvalidation for files that use Password-Based Message Authentication Code 1\n(PBMAC1) integrity mechanism allowing a certificate and private key forgery.\n\nImpact Summary: An attacker impersonating a user can cause a service reading\nPKCS#12 files to accept forged certificates and private keys with a 1 in 256\nprobability.\n\nIf a service accepting PKCS#12 files is using passwords for authenticating\nthe received files, the attacker can create unencrypted PKCS#12 files that\nuse PBMAC1 authentication that specifies an HMAC key of only one byte, allowing\nthem to craft a file that will be accepted with a 1 in 256 probability.\nThat would then cause the service to accept a certificate and private key\ncontrolled by the attacker.\n\nThe FIPS modules are not affected by this issue, as the affected code is\noutside the OpenSSL FIPS module boundary."
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