Open Ticket Request System (OTRS) before 2.3.5 does not properly disable hidden permissions, which allows remote authenticated users to bypass intended queue access restrictions in opportunistic circumstances by visiting a ticket, related to a certain ordering of permission-set and permission-remove operations involving both hidden permissions and other permissions.
The (1) AgentInterface and (2) CustomerInterface components in Open Ticket Request System (OTRS) before 3.0.6 place cleartext credentials into the session data in the database, which makes it easier for context-dependent attackers to obtain sensitive information by reading the _UserLogin and _UserPW fields.
webscript.pl in Open Ticket Request System (OTRS) 2.3.4 and earlier allows remote attackers to execute arbitrary commands via unspecified vectors, related to a "command injection vulnerability."