Fixed in Apache Tomcat 8.5.66

Low: Authentication weakness CVE-2021-30640

Queries made by the JNDI Realm did not always correctly escape parameters. Parameter values could be sourced from user provided data (eg user names) as well as configuration data provided by an administrator. In limited circumstances it was possible for users to authenticate using variations of their user name and/or to bypass some of the protection provided by the LockOut Realm.

This was fixed with commits 24dfb300, 0a272b00, c9f21a2a, 4e86b4ea, 79580e7f, d3407672, 6a9129ac and ad22db64.

This issue was reported publicly as 65224.

Affects: 8.5.0 to 8.5.65