CVE-2025-52556

Estado: AplazadaCrítica (9.3)—

rfc3161-client is a Python library implementing the Time-Stamp Protocol (TSP) described in RFC 3161. Prior to version 1.0.3, there is a flaw in the timestamp response signature verification logic. In particular, chain verification is performed against the TSR's embedded certificates up to the trusted root(s), but fails to verify the TSR's own signature against the timestamping leaf certificates. Consequently, vulnerable versions perform insufficient signature validation to properly consider a TSR verified, as the attacker can introduce any TSR signature so long as the embedded leaf chains up to some root TSA. This issue has been patched in version 1.0.3. There is no workaround for this issue.

CVSS

Versión: 4.0
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/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:X/R:X/V:X/RE:X/U:X
Puntuación base: 9.3

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.17%
Percentil entre todas las CVEs puntuadas: 6
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 principalT1553.006 Code Signing Policy Modificationdefense impairment90 %
Impacto secundarioT1565.001 Stored Data Manipulationimpact75 %

Vulnerabilidad en validación de firmas TSP (CWE-347) accesible remotamente sin autenticación (AV:N/PR:N/UI:N). Permite falsificar sellos de tiempo manipulando la firma, impactando integridad de datos y autenticidad de certificados.

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 Vulnerability Scanning Restrict File and Directory Permissions Restrict Registry Permissions Remote Data Storage Network Segmentation

Tecnologías afectadas (1)

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

Trailofbits — Rfc3161-client^AI

CWE

CWE-347

Referencias

JSON original (NVD)

Mostrar

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  "published": "2025-06-21T02:15:19.947",
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      "value": "rfc3161-client is a Python library implementing the Time-Stamp Protocol (TSP) described in RFC 3161. Prior to version 1.0.3, there is a flaw in the timestamp response signature verification logic. In particular, chain verification is performed against the TSR's embedded certificates up to the trusted root(s), but fails to verify the TSR's own signature against the timestamping leaf certificates. Consequently, vulnerable versions perform insufficient signature validation to properly consider a TSR verified, as the attacker can introduce any TSR signature so long as the embedded leaf chains up to some root TSA. This issue has been patched in version 1.0.3. There is no workaround for this issue."
    },
    {
      "lang": "es",
      "value": "rfc3161-client es una librería de Python que implementa el Protocolo de Marca de Tiempo (TSP) descrito en el RFC 3161. En versiones anteriores a la 1.0.3, existía una falla en la lógica de verificación de firma de la respuesta de marca de tiempo. En particular, la verificación en cadena se realiza con los certificados integrados del TSR hasta la raíz de confianza, pero no verifica la propia firma del TSR con los certificados hoja de marca de tiempo. Por consiguiente, las versiones vulnerables realizan una validación de firma insuficiente para considerar correctamente un TSR verificado, ya que el atacante puede introducir cualquier firma del TSR siempre que la hoja integrada se encadene hasta algún TSA raíz. Este problema se ha corregido en la versión 1.0.3. No existe una solución alternativa."
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  "lastModified": "2026-06-17T09:36:40.210",
  "sourceIdentifier": "security-advisories@github.com"
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