The porte_plume plugin used by SPIP before 4.30-alpha2, 4.2.13, and 4.1.16 is vulnerable to an arbitrary code execution vulnerability. A remote and unauthenticated attacker can execute arbitrary PHP as the SPIP user by sending a crafted HTTP request.
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
Access control involves the use of several protection mechanisms such as:
When any mechanism is not applied or otherwise fails, attackers can compromise the security of the product by gaining privileges, reading sensitive information, executing commands, evading detection, etc. There are two distinct behaviors that can introduce access control weaknesses: