Atlassian JIRA: CSRF in Application Links plugin allows network enumeration (CVE-2019-20100)

The Atlassian Application Links plugin is vulnerable to cross-site request forgery (CSRF). The following versions are affected: all versions prior to 5.4.21, from version 6.0.0 before version 6.0.12, from version 6.1.0 before version 6.1.2, from version 7.0.0 before version 7.0.2, and from version 7.1.0 before version 7.1.3. The vulnerable plugin is used by Atlassian Jira Server and Data Center before version 8.7.0. An attacker could exploit this by tricking an administrative user into making malicious HTTP requests, allowing the attacker to enumerate hosts and open ports on the internal network where Jira server is present.