An issue was discovered in Open Ticket Request System (OTRS) 7.0.x through 7.0.7, Community Edition 6.0.x through 6.0.19, and Community Edition 5.0.x through 5.0.36. An attacker could send a malicious email to an OTRS system. If a logged-in agent user quotes it, the email could cause the browser to load external image resources.
lists.opensuse.org/opensuse-security-announce/2020-04/msg00038.html
lists.opensuse.org/opensuse-security-announce/2020-09/msg00066.html
lists.opensuse.org/opensuse-security-announce/2020-09/msg00077.html
lists.debian.org/debian-lts-announce/2019/06/msg00004.html
lists.debian.org/debian-lts-announce/2023/08/msg00040.html
www.otrs.com/category/release-and-security-notes-en/