CVE-2021-23937

HighCVSS 7.5/10Last modified Jun 17, 2026

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.

Metrics

CVSS 3.1 7.5/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness enumeration

CWE-200

Affected software

Vendor	Product	Versions
Apache Software Foundation	Apache Wicket	>= Apache Wicket 9.x, <= 9.2.0; >= Apache Wicket 8.x, <= 8.11.0; >= Apache Wicket 7.x, <= 7.17.0; >= 6.2.0, < Apache Wicket 6.x*

References

Timeline

Published: May 25, 2021
Last modified: Jun 17, 2026
NVD status: Modified

Related CVEs from 2021

CVE-2021-23949.8Vulnerability in the Oracle WebLogic Server product of Oracle Fusion Middleware (component: Core). Supported versions that are affected are CVE-2021-23958.1Vulnerability in the Oracle Hospitality Reporting and Analytics product of Oracle Food and Beverage Applications (component: iCare, Configur CVE-2021-239534.3If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin information, when said informa CVE-2021-239548.8Using the new logical assignment operators in a JavaScript switch statement could have caused a type confusion, leading to a memory corrupti CVE-2021-239556.1The browser could have been confused into transferring a pointer lock state into another tab, which could have lead to clickjacking attacks.CVE-2021-239566.5An ambiguous file picker design could have confused users who intended to select and upload a single file into uploading a whole directory. CVE-2021-239577.4Navigations through the Android-specific `intent` URL scheme could have been misused to escape iframe sandbox. Note: This issue only affecte CVE-2021-239586.5The browser could have been confused into transferring a screen sharing state into another tab, which would leak unintended information. Thi CVE-2021-239596.1An XSS bug in internal error pages could have led to various spoofing attacks, including other error pages and the address bar. Note: This i CVE-2021-23968.8Vulnerability in the Oracle BI Publisher product of Oracle Fusion Middleware (component: E-Business Suite - XDO). Supported versions that ar CVE-2021-239608.8Performing garbage collection on re-declared JavaScript variables resulted in a user-after-poison, and a potentially exploitable crash. This CVE-2021-239617.4Further techniques that built on the slipstream research combined with a malicious webpage could have exposed both an internal network's hos