The RSS Feed macro in Atlassian Confluence before version 6.5.2 allows remote attackers to inject arbitrary HTML or JavaScript via cross site scripting (XSS) vulnerabilities in various rss properties which were used as links without restriction on their scheme.

Acknowledgements

Atlassian would like to credit Glenn 'devalias' Grant (http://devalias.net) of TSS (https://dtss.com.au) for reporting this issue to us.