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.

Affected Software

VendorProductVersion RangeStatus
Apache Software FoundationApache WicketApache Wicket 9.x <= 9.2.0affected
Apache Software FoundationApache WicketApache Wicket 8.x <= 8.11.0affected
Apache Software FoundationApache WicketApache Wicket 7.x <= 7.17.0affected
Apache Software FoundationApache Wicket6.2.0 < Apache Wicket 6.x*affected

Weaknesses

  • DNS proxy and possible amplification attack

Workarounds

Sanitize the X-Forwarded-For header by running an Apache Wicket application behind a reverse HTTP proxy. 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.

ADP Enrichment

CVE Program Container

Additional References

References