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CVE-2002-1336

Status: ModifiedHigh (7.5)—

TightVNC before 1.2.6 generates the same challenge string for multiple connections, which allows remote attackers to bypass VNC authentication by sniffing the challenge and response of other users.

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 (1)

Tightvnc — Tightvnc

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2002-1336",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 7.5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 6.4,
        "baseSeverity": "HIGH",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": true,
        "userInteractionRequired": false
      }
    ]
  },
  "affected": [
    {
      "source": "cve@mitre.org",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ]
    }
  ],
  "published": "2002-12-11T05:00:00.000",
  "references": [
    {
      "url": "http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000640",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://marc.info/?l=bugtraq&m=102753170201524&w=2",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://marc.info/?l=bugtraq&m=102769183913594&w=2",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.mandrakesoft.com/security/advisories?name=MDKSA-2003:022",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.redhat.com/support/errata/RHSA-2002-287.html",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.redhat.com/support/errata/RHSA-2003-041.html",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.securityfocus.com/bid/5296",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://www.tightvnc.com/WhatsNew.txt",
      "source": "cve@mitre.org"
    },
    {
      "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/5992",
      "source": "cve@mitre.org"
    },
    {
      "url": "http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000640",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://marc.info/?l=bugtraq&m=102753170201524&w=2",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://marc.info/?l=bugtraq&m=102769183913594&w=2",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.mandrakesoft.com/security/advisories?name=MDKSA-2003:022",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.redhat.com/support/errata/RHSA-2002-287.html",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.redhat.com/support/errata/RHSA-2003-041.html",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.securityfocus.com/bid/5296",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.tightvnc.com/WhatsNew.txt",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/5992",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-Other"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "TightVNC before 1.2.6 generates the same challenge string for multiple connections, which allows remote attackers to bypass VNC authentication by sniffing the challenge and response of other users."
    },
    {
      "lang": "es",
      "value": "TightVNC anterior a 1.2.6 genera la misma cadena de desafío a múltiples conexiones, lo que permite a atacantes remotos evitar la autenticación VNC espiando el desafio y la respuesta de otros usuarios."
    }
  ],
  "lastModified": "2026-06-16T21:59:07.640",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:tightvnc:tightvnc:1.2.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B2F4EE57-DA68-4438-A401-BAC82B7242D2"
            },
            {
              "criteria": "cpe:2.3:a:tightvnc:tightvnc:1.2.1:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F9E11A57-016E-4720-A266-A53743629CD8"
            },
            {
              "criteria": "cpe:2.3:a:tightvnc:tightvnc:1.2.3:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "AF990CCF-70BE-46F6-9360-ECC39B6D6F3B"
            },
            {
              "criteria": "cpe:2.3:a:tightvnc:tightvnc:1.2.4:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "0274E35A-ACAB-43F5-A4F3-383CA9EEA1CC"
            },
            {
              "criteria": "cpe:2.3:a:tightvnc:tightvnc:1.2.5:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "0FD5B03E-D897-4A06-A3EF-62B13B46B7EF"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "cve@mitre.org"
}