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CVE-2025-3935

Estado: AnalizadaAlta (7.2)⚠ Explotación activa

ScreenConnect versions 25.2.3 and earlier versions may be susceptible to a ViewState code injection attack. ASP.NET Web Forms use ViewState to preserve page and control state, with data encoded using Base64 protected by machine keys.  It is important to note that to obtain these machine keys, privileged system level access must be obtained.

If these machine keys are compromised, attackers could create and send a malicious ViewState to the website, potentially leading to remote code execution on the server.

The risk does not originate from a vulnerability introduced by ScreenConnect, but from platform level behavior.  This had no direct impact to ScreenConnect Client. ScreenConnect 2025.4 patch disables ViewState and removes any dependency on it.

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).

CISA KEV — explotada activamente

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

AV:N con PR:H y CWE-502 indica desencadenamiento remoto en servicio tras obtener claves de máquina. RCE en servidor ASP.NET mediante inyección de ViewState malicioso confirmado en descripción.

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

Vulnerability ScanningThreat Intelligence ProgramPrivileged Account ManagementNetwork SegmentationExecution PreventionDisable or Remove Feature or Program

Tecnologías afectadas (1)

Connectwise — Screenconnect

CWE

Referencias

JSON original (NVD)

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  "published": "2025-04-25T19:15:49.143",
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      "value": "ScreenConnect versions 25.2.3 and earlier versions may be susceptible to a ViewState code injection attack. ASP.NET Web Forms use ViewState to preserve page and control state, with data encoded using Base64 protected by machine keys. \nIt is important to note that to obtain these machine keys, privileged system level access must be obtained. \n\n\n\nIf these machine keys are compromised, attackers could create and send a malicious ViewState to the website, potentially leading to remote code execution on the server. \n\n\n\nThe risk does not originate from a vulnerability introduced by ScreenConnect, but from platform level behavior.  This had no direct impact to ScreenConnect Client. ScreenConnect 2025.4 patch disables ViewState and removes any dependency on it."
    },
    {
      "lang": "es",
      "value": "Las versiones 25.2.3 y anteriores de ScreenConnect pueden ser susceptibles a un ataque de inyección de código de ViewState. Los formularios web ASP.NET utilizan ViewState para preservar el estado de las páginas y los controles, con datos codificados en Base64 protegidos por claves de máquina. Es importante tener en cuenta que para obtener estas claves de máquina, se requiere acceso privilegiado al sistema. Si estas claves de máquina se ven comprometidas, los atacantes podrían crear y enviar un ViewState malicioso al sitio web, lo que podría provocar la ejecución remota de código en el servidor. El riesgo no se debe a una vulnerabilidad introducida por ScreenConnect, sino a un comportamiento a nivel de plataforma. Esto no tuvo un impacto directo en el cliente de ScreenConnect. El parche 2025.4 de ScreenConnect deshabilita ViewState y elimina cualquier dependencia de él."
    }
  ],
  "lastModified": "2026-06-17T09:20:57.337",
  "cisaActionDue": "2025-06-23",
  "cisaExploitAdd": "2025-06-02",
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  "sourceIdentifier": "7d616e1a-3288-43b1-a0dd-0a65d3e70a49",
  "cisaRequiredAction": "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.",
  "cisaVulnerabilityName": "ConnectWise ScreenConnect Improper Authentication Vulnerability"
}