The IconUriServlet of the Atlassian OAuth Plugin from version 1.3.0 before version 1.9.12 and from version 2.0.0 before version 2.0.4 allows remote attackers to access the content of internal network resources and/or perform an XSS attack via Server Side Request Forgery (SSRF).
dontpanic.42.nl/2017/12/there-is-proxy-in-your-atlassian.html
ecosystem.atlassian.net/browse/OAUTH-344
medium.com/bugbountywriteup/piercing-the-veil-server-side-request-forgery-to-niprnet-access-171018bca2c3
twitter.com/ankit_anubhav/status/973566620676382721
twitter.com/Zer0Security/status/983529439433777152