Security advisory

{
  "id": "46e969b04cf355f7248a99e9fa9caee90fa7671f22b49a8f305b754ad9a196f5",
  "url": "https://osv.dev/vulnerability/CVE-2018-6198",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2018-6198",
    "summary": "w3m through 0.5.3 does not properly handle temporary files when the ~/.w3m directory is unwritable, which allows a local attacker to craft a symlink attack to overwrite arbitrary files.",
    "evidence": "osv:CVE-2018-6198",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2018-6198",
      "aliases": [
        "CVE-2018-6198"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/tats/w3m",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "5397d09e585a1938fb64bc9c5cd5daed1959eb90"
                },
                {
                  "fixed": "18dcbadf2771cdb0c18509b14e4e73505b242753"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:tats:w3m:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "0.5.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "18dcbadf2771cdb0c18509b14e4e73505b242753"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "upstream/0.5.3",
            "upstream/0.5.2",
            "upstream/0.5.1",
            "upstream/0.3",
            "upstream/0.1.10+0.1.11pre+kokb23"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-6198.json",
            "vanir_signatures": [
              {
                "id": "CVE-2018-6198-021bacd2",
                "digest": {
                  "length": 270,
                  "function_hash": "299411999929596845984512423028642050106"
                },
                "source": "https://github.com/tats/w3m/commit/18dcbadf2771cdb0c18509b14e4e73505b242753",
                "target": {
                  "file": "main.c",
                  "function": "w3m_exit"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2018-6198-0bd30630",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "261335769205805046566342251010716909920",
                    "29612917787393137325208173903425113215",
                    "42696203700645889651420809097333495824",
                    "158834774318496427167418388532438585199"
                  ]
                },
                "source": "https://github.com/tats/w3m/commit/18dcbadf2771cdb0c18509b14e4e73505b242753",
                "target": {
                  "file": "rc.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2018-6198-48c324d5",
                "digest": {
                  "length": 1470,
                  "function_hash": "161548505075626386636758859966345807316"
                },
                "source": "https://github.com/tats/w3m/commit/18dcbadf2771cdb0c18509b14e4e73505b242753",
                "target": {
                  "file": "rc.c",
                  "function": "init_rc"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2018-6198-827e47c9",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "132494528490069998977071967010022007597",
                    "82022512250580956341022367886085022917",
                    "332768501774124119740089642761057973044",
                    "294366503126602925986443129707894292652"
                  ]
                },
                "source": "https://github.com/tats/w3m/commit/18dcbadf2771cdb0c18509b14e4e73505b242753",
                "target": {
                  "file": "main.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-20T13:40:05Z"
          }
        }
      ],
      "modified": "2026-10-20T13:40:05.458166722Z",
      "provider": "osv",
      "references": [
        "https://usn.ubuntu.com/3555-1/",
        "https://usn.ubuntu.com/3555-2/",
        "https://bugs.debian.org/888097",
        "https://github.com/tats/w3m/commit/18dcbadf2771cdb0c18509b14e4e73505b242753",
        "https://salsa.debian.org/debian/w3m/commit/18dcbadf2771cdb0c18509b14e4e73505b242753"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*",
              "cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*",
              "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*",
              "cpe:2.3:o:canonical:ubuntu_linux:17.10:*:*:*:*:*:*:*"
            ],
            "vendor_product": "canonical:ubuntu_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "12.04"
                  },
                  {
                    "last_affected": "12.04"
                  },
                  {
                    "introduced": "14.04"
                  },
                  {
                    "last_affected": "14.04"
                  },
                  {
                    "introduced": "16.04"
                  },
                  {
                    "last_affected": "16.04"
                  },
                  {
                    "introduced": "17.10"
                  },
                  {
                    "last_affected": "17.10"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2018-6198",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 387941,
  "published_at": "2018-01-25T03:29:00.697+00:00"
}