An issue was discovered in MantisBT before 2.24.4. Due to insufficient access-level checks, any logged-in user allowed to perform Group Actions can get access to the Summary fields of private Issues via bug_arr[]= in a crafted bug_actiongroup_page.php URL. (The target Issues can have Private view status, or belong to a private Project.)
An issue was discovered in MantisBT before 2.24.4. An incorrect access check in bug_revision_view_page.php allows an unprivileged attacker to view the Summary field of private issues, as well as bugnotes revisions, gaining access to potentially confidential information via the bugnote_id parameter.