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CVE-2016-6271

Status: ModifiedHigh (7.5)—PoC
Severity7.5High · CVSS 3.0
Exploitation probability2.23 %higher than 83% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitAvailableProof of concept on GitHub (unverified)

The Bzrtp library (aka libbzrtp) 1.0.x before 1.0.4 allows man-in-the-middle attackers to conduct spoofing attacks by leveraging a missing HVI check on DHPart2 packet reception.

CVSS

Base score
7.5
Version
3.0
Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
2.23 %
Percentile among all scored CVEs
83
Score date
10/24/2026

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).

Public exploits

Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.

⚠️ GitHub proofs of concept are not verified: some are fake or contain malware. Never run them outside an isolated lab.

Affected technologies (1)

Bzrtp Project — Bzrtp

CWEs

References

Show 6 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2016-6271",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:N/I:P/A:N",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV30": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.0",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2017-01-18T22:59:00.780",
  "references": [
    {
      "url": "http://www.securityfocus.com/bid/95928",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://github.com/BelledonneCommunications/bzrtp/commit/bbb1e6e2f467ee4bd7b9a8c800e4f07343d7d99b",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "source": "cve@mitre.org"
    },
    {
      "url": "https://github.com/gteissier/CVE-2016-6271",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.securityfocus.com/bid/95928",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/BelledonneCommunications/bzrtp/commit/bbb1e6e2f467ee4bd7b9a8c800e4f07343d7d99b",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://github.com/gteissier/CVE-2016-6271",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-254"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Bzrtp library (aka libbzrtp) 1.0.x before 1.0.4 allows man-in-the-middle attackers to conduct spoofing attacks by leveraging a missing HVI check on DHPart2 packet reception."
    },
    {
      "lang": "es",
      "value": "La librería Bzrtp (también conocida como libbzrtp) 1.0.x en versiones anteriores a 1.0.4 permite a atacantes man-in-the-middle llevar a cabo ataques de suplantación de identidad aprovechando una comprobación HVI desaparecida en la recepción de paquetes DHPart2."
    }
  ],
  "lastModified": "2026-06-17T00:50:44.113",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:bzrtp_project:bzrtp:1.0.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "9536042E-1DA6-4971-85BA-E99A73F877A1"
            },
            {
              "criteria": "cpe:2.3:a:bzrtp_project:bzrtp:1.0.2:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "27EC44AF-7082-4DF3-8ED1-9B380BE2EBDB"
            },
            {
              "criteria": "cpe:2.3:a:bzrtp_project:bzrtp:1.0.3:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D470019E-5647-4D3F-A70D-DC19CBD5F588"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}