{"api_version":"1","generated_at":"2026-06-10T13:41:17+00:00","cve":"CVE-2021-23937","urls":{"html":"https://cve.report/CVE-2021-23937","api":"https://cve.report/api/cve/CVE-2021-23937.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-23937","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-23937"},"summary":{"title":"CVE-2021-23937","description":"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.","state":"PUBLIC","assigner":"security@apache.org","published_at":"2021-05-25 17:15:00","updated_at":"2023-11-07 03:31:00"},"problem_types":["CWE-200"],"metrics":[],"references":[{"url":"https://lists.apache.org/thread.html/r127c0c1f3cb71e5bc619ad1e4b898b97c49758d1f20a54042966473e%40%3Cusers.wicket.apache.org%3E","name":"[wicket-users] 20210526 Re: CVE-2021-23937: Apache Wicket: DNS proxy and possible amplification attack","refsource":"","tags":[],"title":"","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"http://www.openwall.com/lists/oss-security/2021/05/25/2","name":"[oss-security] 20210525 CVE-2021-23937: Apache Wicket: DNS proxy and possible amplification attack","refsource":"MLIST","tags":[],"title":"oss-security - 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This proxy should put the client IP address in the X-Forwarded-For header and not pass through the contents of the header as received by the client."}]},"nvd":{"publishedDate":"2021-05-25 17:15:00","lastModifiedDate":"2023-11-07 03:31:00","problem_types":["CWE-200"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:L/Au:N/C:N/I:N/A:P","accessVector":"NETWORK","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"PARTIAL","baseScore":5},"severity":"MEDIUM","exploitabilityScore":10,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0.0","versionEndIncluding":"6.2.0","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0.0","versionEndIncluding":"7.17.0","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*","versionStartIncluding":"8.0.0","versionEndIncluding":"8.11.0","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:apache:wicket:*:*:*:*:*:*:*:*","versionStartIncluding":"9.0.0","versionEndIncluding":"9.2.0","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"23937","Ordinal":"198691","Title":"CVE-2021-23937","CVE":"CVE-2021-23937","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"23937","Ordinal":"1","NoteData":"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.","Type":"Description","Title":null},{"CveYear":"2021","CveId":"23937","Ordinal":"2","NoteData":"2021-05-25","Type":"Other","Title":"Published"},{"CveYear":"2021","CveId":"23937","Ordinal":"3","NoteData":"2021-05-26","Type":"Other","Title":"Modified"}]}}}