Jenkins Global Variable String Parameter Plugin 1.2 and earlier does not escape the name and description of Global Variable String parameters on views displaying parameters. This results in stored cross-site scripting (XSS) vulnerabilities exploitable by attackers with Item/Configure permission.
Exploitation of these vulnerabilities requires that parameters are listed on another page, like the "Build With Parameters" and "Parameters" pages provided by Jenkins (core), and that those pages are not hardened to prevent exploitation. Jenkins (core) has prevented exploitation of vulnerabilities of this kind on the "Build With Parameters" and "Parameters" pages since 2.44 and LTS 2.32.2 as part of the SECURITY-353 / CVE-2017-2601 fix. Additionally, several plugins have previously been updated to list parameters in a way that prevents exploitation by default, see SECURITY-2617 in the 2022-04-12 security advisory for a list.