SummaryUsers with webhook permissions can conduct SSRF via webhooks. If they have permission to view the webhook logs, the (partial) request response is also disclosed
DetailsWhen sending webhooks, the destination is not validated, causing SSRF.
ImpactBypass of firewalls to interact with internal services. See https://owasp.org/Top10/A10_2021-Server-Side_Request_Forgery_%28SSRF%29/ for more potential impact.
Resources https://cheatsheetseries.owasp.org/cheatsheets/Server_Side_Request_Forgery_Prevention_Cheat_Sheet.html for more information on SSRF and its fix.
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.