The SPIP template composer/compiler in SPIP 3.1.2 and earlier allows remote authenticated users to execute arbitrary PHP code by uploading an HTML file with a crafted (1) INCLUDE or (2) INCLURE tag and then accessing it with a valider_xml action.
www.openwall.com/lists/oss-security/2016/10/05/17
www.openwall.com/lists/oss-security/2016/10/07/5
www.openwall.com/lists/oss-security/2016/10/08/6
www.securityfocus.com/bid/93451
core.spip.net/projects/spip/repository/revisions/23186
core.spip.net/projects/spip/repository/revisions/23189
core.spip.net/projects/spip/repository/revisions/23192
sysdream.com/news/lab/2016-10-19-spip-3-1-2-template-compiler-composer-php-code-execution-cve-2016-7998/