Cisco Secure Access Control System (ACS) 5.x before 5.2 Patch 11 and 5.3 before 5.3 Patch 7, when a certain configuration involving TACACS+ and LDAP is used, does not properly validate passwords, which allows remote attackers to bypass authentication by sending a valid username and a crafted password string, aka Bug ID CSCuc65634.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.