ecrire/exec/valider_xml.php in SPIP 3.1.2 and earlier allows remote attackers to conduct server side request forgery (SSRF) attacks via a URL in the var_url parameter in a valider_xml action.
https://sysdream.com/news/lab/2016-10-19-spip-3-1-2-server-side-request-forgery-cve-2016-7999/
https://core.spip.net/projects/spip/repository/revisions/23193
https://core.spip.net/projects/spip/repository/revisions/23188
http://www.securityfocus.com/bid/93451
http://www.openwall.com/lists/oss-security/2016/10/12/10
http://www.openwall.com/lists/oss-security/2016/10/08/6