SPIP < 4.4.9 Blind Server-Side Request Forgery via Syndicated Sites

SPIP before 4.4.9 allows Blind Server-Side Request Forgery (SSRF) via syndicated sites in the private area. When editing a syndicated site, the application does not verify that the syndication URL is a valid remote URL, allowing an authenticated attacker to make the server issue requests to arbitrary internal or external destinations. This vulnerability is not mitigated by the SPIP security screen.