In spring security versions prior to 5.4.11+, 5.5.7+ , 5.6.4+ and older unsupported versions, RegexRequestMatcher can easily be misconfigured to be bypassed on some servlet containers. Applications using RegexRequestMatcher with `.` in the regular expression are possibly vulnerable to an authorization bypass.

Spring Security versions 5.5.x prior to 5.5.7, 5.6.x prior to 5.6.4, and earlier unsupported versions contain an integer overflow vulnerability. When using the BCrypt class with the maximum work factor (31), the encoder does not perform any salt rounds, due to an integer overflow error. The default settings are not affected by this CVE.

When using the CAS Proxy ticket authentication from Spring Security 3.1 to 3.2.4 a malicious CAS Service could trick another CAS Service into authenticating a proxy ticket that was not associated. This is due to the fact that the proxy ticket authentication uses the information from the HttpServletRequest which is populated based upon untrusted information within the HTTP request. This means if there are access control restrictions on which CAS services can authenticate to one another, those restrictions can be bypassed. If users are not using CAS Proxy tickets and not basing access control decisions based upon the CAS Service, then there is no impact to users.

The ActiveDirectoryLdapAuthenticator in Spring Security 3.2.0 to 3.2.1 and 3.1.0 to 3.1.5 does not check the password length. If the directory allows anonymous binds then it may incorrectly authenticate a user who supplies an empty password.