Security advisory

{
  "id": "585adde512d3431979e30b22221b51f49f731d54dcbe08d186257e6e54b8e82f",
  "url": "https://osv.dev/vulnerability/CVE-2020-28019",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-28019",
    "summary": "Exim 4 before 4.94.2 has Improper Initialization that can lead to recursion-based stack consumption or other consequences. This occurs because use of certain getc functions is mishandled when a client uses BDAT instead of DATA.",
    "evidence": "osv:CVE-2020-28019",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2020-28019",
      "aliases": [
        "CVE-2020-28019"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/exim/exim",
              "type": "GIT",
              "events": [
                {
                  "introduced": "57091745e6d5ce4259c645b3ac63838668d55b7f"
                },
                {
                  "fixed": "919111edac911ba9c15422eafd7c5bf14d416d26"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.88"
                      },
                      {
                        "fixed": "4.94.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "exim-4.94.1",
            "exim-4.94",
            "exim-4.94-RC2",
            "exim-4.94-RC1",
            "exim-4_94_RC0",
            "exim-4.93",
            "exim-4.93-RC7",
            "exim-4.93-RC6",
            "exim-4.93-RC5",
            "exim-4.93-RC4",
            "exim-4.93-RC3",
            "exim-4.93-RC2",
            "exim-4.93-RC1",
            "exim-4.93-RC0",
            "exim-4.92-jgh",
            "exim-4.92-RC6",
            "exim-4.92",
            "exim-4.92-RC5",
            "exim-4.92-RC4",
            "exim-4.92-RC3",
            "exim-4.92-RC2",
            "exim-4.92-RC1",
            "exim-4_91",
            "exim-4_91_RC4",
            "exim-4_91_RC3",
            "exim-4_91_RC2",
            "exim-4_91_RC1",
            "exim-4_90_RC4",
            "exim-4_90",
            "exim-4_90_RC3",
            "exim-4_90_RC2",
            "exim-4_90_RC1",
            "exim-4.90devstart",
            "exim-4_89_RC3",
            "exim-4_89_RC1",
            "exim-4_88"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-28019.json",
            "vanir_signatures": [
              {
                "id": "CVE-2020-28019-a5b97121",
                "digest": {
                  "length": 86,
                  "function_hash": "85807556721849417698167290800033609961"
                },
                "source": "https://github.com/exim/exim/commit/919111edac911ba9c15422eafd7c5bf14d416d26",
                "target": {
                  "file": "src/src/smtp_in.c",
                  "function": "bdat_ungetc"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2020-28019-f33c15e3",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "2970847905863908930961351479348962244",
                    "259127508678304675853565838131490768076",
                    "16856440449629165604374376294870505588",
                    "21031574626938302228709321949938569854",
                    "66694532801356984293692391694813765468",
                    "228435147706632689035739186300622821874",
                    "137018139142916213668559470023354199721",
                    "262955889687131153967951266340364206508",
                    "122233694988885115887188843215612136724",
                    "55546132595750780137850156557040648213",
                    "178043897109541241882122479475000937559",
                    "311496951671523793228361465075141960070"
                  ]
                },
                "source": "https://github.com/exim/exim/commit/919111edac911ba9c15422eafd7c5bf14d416d26",
                "target": {
                  "file": "src/src/smtp_in.c"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-24T14:22:42Z"
          }
        }
      ],
      "modified": "2026-10-24T14:22:42.063663837Z",
      "provider": "osv",
      "references": [
        "https://www.exim.org/static/doc/security/CVE-2020-qualys/CVE-2020-28019-BDATA.txt"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-28019",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 443685,
  "published_at": "2021-05-06T13:15:09.587+00:00"
}