The sourcecache expansion module in MISP Modules (misp-modules) contains a Server-Side Request Forgery (SSRF) vulnerability. When a user with permission to create or modify attributes of type 'link' or 'url' submits an attribute value, the module passes the URL directly to its internal archiving function without any validation of the target address. An attacker can therefore craft a URL pointing to loopback addresses (e.g., 127.0.0.1), private network ranges, link-local addresses, or cloud metadata endpoints (e.g., 169.254.169.254). The MISP server will issue an HTTP request to that target and store the response body in the event, effectively exfiltrating data from internal services to the attacker through the MISP interface. Non-HTTP schemes such as file:// are also accepted, potentially allowing local file disclosure. The vulnerability requires an authenticated MISP user with the ability to create or edit attributes of the affected types. The security impact is information disclosure from internal services reachable by the MISP server, including sensitive data such as cloud credentials, internal application data, or local files.
The fix introduces a URL validation gate (is_safe_url) that is invoked before any archiving request is made. The function restricts the scheme to http or https, resolves the hostname via DNS, and verifies that every resolved IP address is globally routable (i.e., not loopback, private, link-local, or otherwise non-global). If any check fails, the module returns an error and the fetch is never performed, preventing the server from being directed to internal or non-HTTP targets.