CVE-2021-20324

A flaw was found in WildFly Elytron. A variation to the use of a session fixation exploit when using Undertow was found despite Undertow switching the session ID after authentication. The highest threat from this vulnerability is to data confidentiality and integrity.

Mitigation

This attack is dependent on the attacker being able to create a session and the victim accessing the session before the session expires, we do have a 15 minute session timeout by default but the attacker could also keep this alive by say sending in a request every five minutes.

The server by default supports session tracking by URL and Cookie, if the web.xml is updated to support COOKIE only the exploit is not possible by sharing the link.

  <session-config>  
    <tracking-mode>URL</tracking-mode>  
  </session-config>  

TO

  <session-config>  
    <tracking-mode>COOKIE</tracking-mode>  
  </session-config>