MantisBT before 1.2.11 does not check the deleteattachmentsthreshold permission when formsecurityvalidation is set to OFF, which allows remote authenticated users with certain privileges to bypass intended access restrictions and delete arbitrary attachments.
The mcissuenoteupdate function in the SOAP API in MantisBT before 1.2.11 does not properly check privileges, which allows remote attackers with bug reporting privileges to edit arbitrary bugnotes via a SOAP request.
MantisBT before 1.2.9 does not audit when users copy or clone a bug report, which makes it easier for remote attackers to copy bug reports without detection.
The SOAP API in MantisBT before 1.2.9 does not properly enforce the bugnoteallowusereditdelete and deletebugthreshold permissions, which allows remote authenticated users with read and write SOAP API privileges to delete arbitrary bug reports and bug notes.
MantisBT before 1.2.9 does not properly check permissions, which allows remote authenticated users with manager privileges to (1) modify or (2) delete global categories.
The mcichecklogin function in api/soap/mcapi.php in the SOAP API in MantisBT before 1.2.9 allows remote attackers to bypass authentication via a null password.