SSRF Vulnerability in Open Notebook /api/sources Endpoint

Open Notebook versions before 1.11.0 contain a Server-Side Request Forgery (SSRF) vulnerability within the POST /api/sources endpoint. This flaw arises from insufficient validation of the 'URL' parameter, which allows an authenticated user to force the application server to perform arbitrary outbound HTTP requests. By manipulating this parameter, an attacker can proxy requests to interact with internal network services, resources bound to localhost, or sensitive cloud metadata services. Because the request originates from the application server itself, it bypasses network-level access controls that might otherwise protect these internal resources. This vulnerability is particularly critical in cloud-hosted environments where metadata services (such as the AWS Instance Metadata Service) can be used to extract sensitive security credentials or instance information.

Impact

Successful exploitation allows authenticated users to pivot from the application layer into the internal network, potentially accessing restricted management interfaces, services not exposed to the public, or sensitive cloud environment data. This facilitates reconnaissance and potential credential theft, which may lead to further system compromise within the internal infrastructure.

Recommendation

1. Upgrade Open Notebook to version 1.11.0 or later to implement URL validation on the /api/sources endpoint.
2. Review application logs for unusual POST requests to /api/sources where the 'URL' parameter contains private IP ranges (e.g., 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) or common metadata endpoints (e.g., 169.254.169.254).
3. Implement network egress filtering on the application server to restrict outbound connections to only necessary external domains.