From $URL: Multiple Cross Site Scripting issues Missing HTML quoting allows authenticated agents or customers to inject HTML tags. This vulnerability allows an attacker to inject script code into the OTRS web-interface which will be loaded and executed in the browsers of system users. Possible Denial of Service Attack Perl's regular expressions consume 100% CPU time on the server if an agents or customer views an affected article. To exploit this vulnerability the malicious user needs to send extremely large HTML emails to your system address. Affected by these vulnerabilities are all releases of OTRS 2.3.x and 2.4.x up to and including 2.4.7.
*** This bug has been marked as a duplicate of bug 337755 ***