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CVE-2026-39908

Estado: AplazadaAlta (7.1)—

OpenBullet2 through version 0.3.2 on Windows contains a credential disclosure vulnerability that allows remote attackers to capture the NTLMv2 hash of the process user by configuring a job proxy source with a UNC path pointing to an attacker-controlled server. When the job starts, the application attempts to load proxies from the UNC path, triggering an SMB authentication attempt that discloses the NTLMv2 hash, which can then be relayed or cracked offline.

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).

🎯 Técnicas ATT&CK

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

Acceso remoto con privilegios (PR:L) a servicio OpenBullet2 mediante UNC path malicioso que captura hash NTLMv2 del usuario del proceso; se releva o crackea offline.

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 ManagementNetwork SegmentationVulnerability ScanningUser Account ManagementThreat Intelligence ProgramPassword Policies

Tecnologías afectadas (1)

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

Openbullet — Openbullet2AI

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-39908",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-39908",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-06-08T18:06:32.903409Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "disclosure@vulncheck.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 6.5,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 2.8
      }
    ],
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "disclosure@vulncheck.com",
        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
          "baseScore": 7.1,
          "Automatable": "NOT_DEFINED",
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/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",
          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "NONE",
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          "privilegesRequired": "LOW",
          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
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  "affected": [
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      "affectedData": [
        {
          "repo": "https://github.com/openbullet/openbullet2",
          "vendor": "openbullet",
          "product": "openbullet2",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "versionType": "semver",
              "lessThanOrEqual": "0.3.2"
            }
          ],
          "packageURL": "pkg:github/openbullet/openbullet2",
          "defaultStatus": "affected"
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  "published": "2026-06-08T17:16:42.460",
  "references": [
    {
      "url": "https://hackernoon.com/one-empty-header-to-admin-how-an-auth-bypass-breaks-openbullet2",
      "source": "disclosure@vulncheck.com"
    },
    {
      "url": "https://www.vulncheck.com/advisories/openbullet2-ntlmv2-hash-disclosure-via-unc-path-proxy-source",
      "source": "disclosure@vulncheck.com"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
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      "type": "Secondary",
      "source": "disclosure@vulncheck.com",
      "description": [
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          "lang": "en",
          "value": "CWE-522"
        }
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    }
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    {
      "lang": "en",
      "value": "OpenBullet2 through version 0.3.2 on Windows contains a credential disclosure vulnerability that allows remote attackers to capture the NTLMv2 hash of the process user by configuring a job proxy source with a UNC path pointing to an attacker-controlled server. When the job starts, the application attempts to load proxies from the UNC path, triggering an SMB authentication attempt that discloses the NTLMv2 hash, which can then be relayed or cracked offline."
    },
    {
      "lang": "es",
      "value": "OpenBullet2 hasta la versión 0.3.2 en Windows contiene una vulnerabilidad de divulgación de credenciales que permite a atacantes remotos capturar el hash NTLMv2 del usuario del proceso al configurar una fuente de proxy de trabajo con una ruta UNC que apunta a un servidor controlado por el atacante. Cuando el trabajo se inicia, la aplicación intenta cargar proxies desde la ruta UNC, desencadenando un intento de autenticación SMB que divulga el hash NTLMv2, el cual puede ser luego retransmitido o descifrado sin conexión."
    }
  ],
  "lastModified": "2026-07-23T07:10:00.113",
  "sourceIdentifier": "disclosure@vulncheck.com"
}