YesWiki before 4.6.7 contains a server-side request forgery vulnerability that allows unauthenticated attackers to make server-side GET requests by supplying an unvalidated actor URL to the Bazar abonnements sync action. Attackers can target internal hosts or cloud metadata endpoints and chain attacker-controlled outbox first/next links, with fetched responses stored as readable Bazar entries.
Weakness
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.