send_email in graphite-web/webapp/graphite/composer/views.py is vulnerable to SSRF. The vulnerable SSRF endpoint can be used by an attacker to have the Graphite web server request any resource. The response to this SSRF request is encoded into an image file and then sent to an e-mail address that can be supplied by the attacker. Thus, an attacker can exfiltrate any information.
Created graphite-web tracking bugs for this issue:
Affects: epel-7 [bug 2001848]
Upstream PR: https://github.com/graphite-project/graphite-web/pull/2499