CVE-2021-22696: 
Java vulnerability analysis and mitigation

CVE-2021-22696 affects Apache CXF, discovered and disclosed in April 2021. The vulnerability exists in CXF's JwtRequestCodeFilter component, which supports passing OAuth 2 parameters via JWT tokens. The issue affects Apache CXF versions prior to 3.4.3 and versions prior to 3.3.10 (Apache Security).

The vulnerability stems from insufficient validation of the 'request_uri' parameter in the OAuth 2 authorization process. While CXF ensures the parameter uses HTTPS, it makes a REST request to retrieve a JWT token without proper validation, as specified in section 10.4.1 of the OAuth 2.0 Authorization Framework: JWT Secured Authorization Request (JAR) specification (CVE Details).

The vulnerability exposes the authorization server to potential Distributed Denial of Service (DDoS) attacks. When exploited, attackers could leverage the insufficient validation to orchestrate DDoS attacks against the authorization server (Apache Security).

The vulnerability has been patched in Apache CXF versions 3.4.3 and 3.3.10. Organizations using affected versions should upgrade to these or later versions to mitigate the vulnerability. The fix includes proper validation of the request_uri parameter as specified in the OAuth 2.0 JAR specification (Apache Security).