Security advisory

{
  "id": "91c45d86b9226da536316c3a583e96fed72876fa81a71304e2650dc4af494bf4",
  "url": "https://osv.dev/vulnerability/CVE-2021-31618",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-31618",
    "summary": "Apache HTTP Server protocol handler for the HTTP/2 protocol checks received request headers against the size limitations as configured for the server and used for the HTTP/1 protocol as well. On violation of these restrictions and HTTP response is sent to the client with a status code indicating why the request was rejected. This rejection response was not fully initialised in the HTTP/2 protocol handler if the offending header was the very first one received or appeared in a a footer. This led to a NULL pointer dereference on initialised memory, crashing reliably the child process. Since such a triggering HTTP/2 request is easy to craft and submit, this can be exploited to DoS the server. This issue affected mod_http2 1.15.17 and Apache HTTP Server version 2.4.47 only. Apache HTTP Server 2.4.47 was never released.",
    "evidence": "osv:CVE-2021-31618",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-31618",
      "aliases": [
        "BIT-apache-2021-31618",
        "CVE-2021-31618"
      ],
      "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/apache/httpd",
              "type": "GIT",
              "events": [
                {
                  "introduced": "f442d2ad7489aa917a6113d016805dbd110b706c"
                },
                {
                  "last_affected": "f442d2ad7489aa917a6113d016805dbd110b706c"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:apache:http_server:2.4.47:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.4.47"
                      },
                      {
                        "last_affected": "2.4.47"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.4.47"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-31618.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:15.112250391Z",
      "provider": "osv",
      "references": [
        "https://lists.apache.org/thread.html/r14b66ef0f4f569fd515a3f96cd4eb58bd9a8ff525cc326bb0359664f%40%3Ccvs.httpd.apache.org%3E",
        "https://lists.apache.org/thread.html/r783b6558abf3305b17ea462bed4bd66d82866438999bf38cef6d11d1%40%3Ccvs.httpd.apache.org%3E",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2NKJ3ZA3FTSZ2QBBPKS6BYGAWYRABNQQ/",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A73QJ4HPUMU26I6EULG6SCK67TUEXZYR/",
        "https://lists.debian.org/debian-lts-announce/2021/07/msg00006.html",
        "https://seclists.org/oss-sec/2021/q2/206",
        "https://security.gentoo.org/glsa/202107-38",
        "https://security.netapp.com/advisory/ntap-20210727-0008/",
        "https://www.debian.org/security/2021/dsa-4937",
        "https://www.oracle.com/security-alerts/cpuoct2021.html"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:a:apache:http_server:1.15.17:*:*:*:*:*:*:*"
            ],
            "vendor_product": "apache:http_server",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "1.15.17"
                  },
                  {
                    "last_affected": "1.15.17"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          {
            "cpes": [
              "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
              "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "9.0"
                  },
                  {
                    "last_affected": "9.0"
                  },
                  {
                    "introduced": "10.0"
                  },
                  {
                    "last_affected": "10.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          {
            "cpes": [
              "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*",
              "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*"
            ],
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "33"
                  },
                  {
                    "last_affected": "33"
                  },
                  {
                    "introduced": "34"
                  },
                  {
                    "last_affected": "34"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          {
            "cpes": [
              "cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "oracle:enterprise_manager_ops_center",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "12.4.0.0"
                  },
                  {
                    "last_affected": "12.4.0.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          {
            "cpes": [
              "cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:*",
              "cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:*",
              "cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*"
            ],
            "vendor_product": "oracle:instantis_enterprisetrack",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "17.1"
                  },
                  {
                    "last_affected": "17.1"
                  },
                  {
                    "introduced": "17.2"
                  },
                  {
                    "last_affected": "17.2"
                  },
                  {
                    "introduced": "17.3"
                  },
                  {
                    "last_affected": "17.3"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          },
          {
            "cpes": [
              "cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*"
            ],
            "vendor_product": "oracle:zfs_storage_appliance_kit",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "8.8"
                  },
                  {
                    "last_affected": "8.8"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-31618",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 429103,
  "published_at": "2021-06-15T09:15:07.96+00:00"
}