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CVE-2018-6307

Status: ModifiedHigh (8.1)—

LibVNC before commit ca2a5ac02fbbadd0a21fabba779c1ea69173d10b contains heap use-after-free vulnerability in server code of file transfer extension that can result remote code execution.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (3)

Canonical — Ubuntu LinuxDebian — Debian LinuxLibvnc Project — Libvncserver

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2018-6307",
  "cveTags": [],
  "metrics": {
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        "source": "nvd@nist.gov",
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          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:M/Au:N/C:P/I:P/A:P",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 6.4,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 8.6,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
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    "cvssMetricV30": [
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        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
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          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.2
      }
    ]
  },
  "affected": [
    {
      "source": "vulnerability@kaspersky.com",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "LibVNC",
          "versions": [
            {
              "status": "affected",
              "version": "commit ca2a5ac02fbbadd0a21fabba779c1ea69173d10b"
            }
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  "published": "2018-12-19T16:29:00.593",
  "references": [
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      "url": "https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-026-libvnc-heap-use-after-free/",
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      "source": "vulnerability@kaspersky.com"
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      "url": "https://usn.ubuntu.com/3877-1/",
      "tags": [
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      "source": "vulnerability@kaspersky.com"
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    },
    {
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      "tags": [
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      "source": "nvd@nist.gov"
    },
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      "tags": [
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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  ],
  "vulnStatus": "Modified",
  "weaknesses": [
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      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "LibVNC before commit ca2a5ac02fbbadd0a21fabba779c1ea69173d10b contains heap use-after-free vulnerability in server code of file transfer extension that can result remote code execution."
    },
    {
      "lang": "es",
      "value": "LibVNC antes del commit con ID ca2a5ac02fbbadd0a21fabba779c1ea69173d10b contiene una vulnerabilidad de uso de memoria dinámica (heap) previamente liberada en el código del servidor de la extensión de transferencia de archivos que puede resultar en la ejecución remota de código."
    }
  ],
  "lastModified": "2026-06-17T02:01:38.420",
  "configurations": [
    {
      "nodes": [
        {
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  "sourceIdentifier": "vulnerability@kaspersky.com"
}