SPIP 2.x before 2.1.19, 3.0.x before 3.0.22, and 3.1.x before 3.1.1 allows remote attackers to execute arbitrary PHP code by adding content, related to the filtrerentites function.
The encodercontexteajax function in ecrire/inc/filtres.php in SPIP 2.x before 2.1.19, 3.0.x before 3.0.22, and 3.1.x before 3.1.1 allows remote attackers to conduct PHP object injection attacks and execute arbitrary PHP code via a crafted serialized object.
SPIP 3.0.x before 3.0.9, 2.1.x before 2.1.22, and 2.0.x before 2.0.23 allows remote attackers to gain privileges and "take editorial control" via vectors related to ecrire/inc/filtres.php.
SPIP 1.9 before 1.9.2i and 2.0.x through 2.0.8 does not use proper access control for (1) ecrire/exec/install.php and (2) ecrire/index.php, which allows remote attackers to conduct unauthorized activities related to installation and backups, as exploited in the wild in August 2009.
Cross-site request forgery (CSRF) vulnerability in ecrire/action/logout.php in SPIP before 2.1.24 allows remote attackers to hijack the authentication of arbitrary users for requests that logout the user via unspecified vectors.
Cross-site scripting (XSS) vulnerability in the author page (prive/formulaires/editerauteur.php) in SPIP before 2.1.24 and 3.0.x before 3.0.12 allows remote attackers to inject arbitrary web script or HTML via the urlsite parameter.