Open Ticket Request System (OTRS) 4.0.x before 4.0.33, 5.0.x before 5.0.31, and 6.0.x before 6.0.13 allows an authenticated user to delete files via a modified submission form because upload caching is mishandled.

Open Ticket Request System (OTRS) 6.0.x before 6.0.13 allows an admin to conduct an XSS attack via a modified URL.

Open Ticket Request System (OTRS) 4.0.x before 4.0.33 and 5.0.x before 5.0.31 allows an admin to conduct an XSS attack via a modified URL because user and customer preferences are mishandled.

In Open Ticket Request System (OTRS) 4.0.x before 4.0.32, 5.0.x before 5.0.30, and 6.0.x before 6.0.11, an attacker could send a malicious email to an OTRS system. If a user with admin permissions opens it, it causes deletions of arbitrary files that the OTRS web server user has write access to.

In Open Ticket Request System (OTRS) 4.0.x before 4.0.32, 5.0.x before 5.0.30, and 6.0.x before 6.0.11, an attacker could send a malicious email to an OTRS system. If a logged in user opens it, the email could cause the browser to load external image or CSS resources.

An issue was discovered in Open Ticket Request System (OTRS) 6.0.x through 6.0.9, 5.0.x through 5.0.28, and 4.0.x through 4.0.30. An attacker who is logged into OTRS as an agent may escalate their privileges by accessing a specially crafted URL.