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 validerxml action.

Cross-site request forgery (CSRF) vulnerability in ecrire/exec/validerxml.php in SPIP 3.1.2 and earlier allows remote attackers to hijack the authentication of administrators for requests that execute the XML validator on a local file via a crafted validerxml request. NOTE: this issue can be combined with CVE-2016-7998 to execute arbitrary PHP code.

ecrire/exec/validerxml.php in SPIP 3.1.2 and earlier allows remote attackers to conduct server side request forgery (SSRF) attacks via a URL in the varurl parameter in a validerxml action.

Cross-site scripting (XSS) vulnerability in validerxml.php in SPIP 3.1.2 and earlier allows remote attackers to inject arbitrary web script or HTML via the varurl parameter in a validerxml action.

Directory traversal vulnerability in ecrire/exec/validerxml.php in SPIP 3.1.2 and earlier allows remote attackers to enumerate the files on the system via the varurl parameter in a validerxml action.