Security advisory

{
  "id": "249aabc19aaaf47c4de82af5e729fd1f222318da4f572fd3a1c3df55bb6fda67",
  "url": "https://osv.dev/vulnerability/CVE-2021-23937",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-23937",
    "summary": "A DNS proxy and possible amplification attack vulnerability in WebClientInfo of Apache Wicket allows an attacker to trigger arbitrary DNS lookups from the server when the X-Forwarded-For header is not properly sanitized. This DNS lookup can be engineered to overload an internal DNS server or to slow down request processing of the Apache Wicket application causing a possible denial of service on either the internal infrastructure or the web application itself. This issue affects Apache Wicket Apache Wicket 9.x version 9.2.0 and prior versions; Apache Wicket 8.x version 8.11.0 and prior versions; Apache Wicket 7.x version 7.17.0 and prior versions and Apache Wicket 6.x version 6.2.0 and later versions.",
    "evidence": "osv:CVE-2021-23937",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-23937",
      "aliases": [
        "CVE-2021-23937",
        "GHSA-hmhg-95wh-r699"
      ],
      "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/wicket",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0d75ee57abb31b4db48c0396870aba39c4d9ddee"
                },
                {
                  "last_affected": "79154ff0ef8c920f586dd88d87dd9afad91b6dac"
                },
                {
                  "introduced": "98a3a6295f426aa25a121f914a41bf792df8fdb0"
                },
                {
                  "last_affected": "2d92f60565fc0c5d5954ce6f313555b596197d6d"
                },
                {
                  "introduced": "5e789f1c98f6d57dba17f896c6220b0202af08a9"
                },
                {
                  "last_affected": "34f78c853500356135918ef16356bd669bb96422"
                },
                {
                  "introduced": "c2802f3ef8df9833da63d144fb4ad03d59e31acc"
                },
                {
                  "last_affected": "bb7560bda91fb06f9c6107530947c73aaf4154db"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "6.0.0"
                      },
                      {
                        "last_affected": "6.2.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "7.0.0"
                      },
                      {
                        "last_affected": "7.17.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "8.0.0"
                      },
                      {
                        "last_affected": "8.11.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "9.0.0"
                      },
                      {
                        "last_affected": "9.2.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-23937.json"
          }
        }
      ],
      "modified": "2026-10-24T10:31:06.017309834Z",
      "provider": "osv",
      "references": [
        "https://lists.apache.org/thread.html/r127c0c1f3cb71e5bc619ad1e4b898b97c49758d1f20a54042966473e%40%3Cannounce.wicket.apache.org%3E",
        "https://lists.apache.org/thread.html/r127c0c1f3cb71e5bc619ad1e4b898b97c49758d1f20a54042966473e%40%3Cusers.wicket.apache.org%3E",
        "https://lists.apache.org/thread.html/r8ccbd91b56ebf045d151bd4282bfeea7842a0698a0b76118fca8fe78%40%3Cdev.wicket.apache.org%3E",
        "https://lists.apache.org/thread.html/rc2ef22f90793e158cef65a7e370cdbca023c499d1403d65feeca870d%40%3Cusers.wicket.apache.org%3E"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-23937",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 440900,
  "published_at": "2021-05-25T17:15:08.187+00:00"
}