Security advisory

{
  "id": "8e7ac87974895fc4eb47c65a1b6f45cbf53f7a3d63920ed17fb50c727f09637f",
  "url": "https://osv.dev/vulnerability/CVE-2017-17439",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2017-17439",
    "summary": "In Heimdal through 7.4, remote unauthenticated attackers are able to crash the KDC by sending a crafted UDP packet containing empty data fields for client name or realm. The parser would unconditionally dereference NULL pointers in that case, leading to a segmentation fault. This is related to the _kdc_as_rep function in kdc/kerberos5.c and the der_length_visible_string function in lib/asn1/der_length.c.",
    "evidence": "osv:CVE-2017-17439",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2017-17439",
      "aliases": [
        "CVE-2017-17439"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/heimdal/heimdal",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "a3d72c604378e0bff787cc426f2b17f75b112dce"
                },
                {
                  "fixed": "1a6a6e462dc2ac6111f9e02c6852ddec4849b887"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:heimdal_project:heimdal:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "7.4.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "1a6a6e462dc2ac6111f9e02c6852ddec4849b887"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "heimdal-1.3.0pre1",
            "heimdal-7.4.0",
            "heimdal-7.3.0",
            "heimdal-7.2.0",
            "heimdal-7.1.0",
            "heimdal-7.0.3",
            "heimdal-7.0.2",
            "heimdal-7.0.1",
            "heimdal-7.1rc1",
            "git2svn-syncpoint-master",
            "heimdal-1.5pre2",
            "heimdal-1.5pre1",
            "upstream-1.4.0+git20110220.dfsg.1",
            "upstream-1.4.0+git20101228.dfsg.1",
            "heimdal-1.3.0rc1",
            "heimdal-1.3.0pre11",
            "heimdal-1.3.0pre10",
            "heimdal-1.3.0pre9",
            "heimdal-1.3.0pre8",
            "heimdal-1.3.0pre7",
            "heimdal-1.3.0pre6",
            "heimdal-1.3.0pre5",
            "heimdal-1.3.0pre4",
            "heimdal-1.3.0pre3",
            "switch-from-svn-to-git"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2017-17439.json",
            "vanir_signatures": [
              {
                "id": "CVE-2017-17439-45d566d2",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "184552108741995966909798273234929043718",
                    "31157069625652692581562993520782672132",
                    "92289731964834894266176103875665865520",
                    "220543229444911101941918136132963866440",
                    "68088921273738415772594604441004796928",
                    "289623454940078461526621765045642131000",
                    "19653521005183287255750554540954066757",
                    "238734535077344973939955929287016383729",
                    "198986556732662134247394704136678794791",
                    "172798049371050135097062238087022251110",
                    "333345530607291890332505461811148112806",
                    "197736238020111757745263551938246121115"
                  ]
                },
                "source": "https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887",
                "target": {
                  "file": "kdc/kerberos5.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2017-17439-fa1b0857",
                "digest": {
                  "length": 15811,
                  "function_hash": "319009278022935075940704152087705260197"
                },
                "source": "https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887",
                "target": {
                  "file": "kdc/kerberos5.c",
                  "function": "_kdc_as_rep"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-20T13:21:16Z"
          }
        }
      ],
      "modified": "2026-10-20T13:21:16.119238134Z",
      "provider": "osv",
      "references": [
        "https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887",
        "https://www.debian.org/security/2017/dsa-4055",
        "https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144",
        "https://github.com/heimdal/heimdal/issues/353"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "9.0"
                  },
                  {
                    "last_affected": "9.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2017-17439",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 387552,
  "published_at": "2017-12-06T15:29:00.25+00:00"
}