Attacker is able craft an article with a link to the customer address book with malicious content (JavaScript). When agent opens the link, JavaScript code is executed due to the missing parameter encoding. This issue affects: ((OTRS)) Community Edition: 6.0.26 and prior versions. OTRS: 7.0.15 and prior versions.
Upgrade to OTRS 7.0.16, ((OTRS)) Community Edition 6.0.27
Patch for ((OTRS)) Community Edition 6: https://github.com/OTRS/otrs/commit/2576830053f70a3a9251558e55f34843dec61aa2