An authenticated Server-Side Request Forgery vulnerability in Open Notebook allows attackers to perform unauthorized requests to internal services and cloud metadata endpoints.

The application fails to properly validate the URL parameter within the POST /api/sources endpoint. This flaw allows an authenticated user to force the server to initiate arbitrary HTTP requests to internal network services, localhost-bound services, or cloud infrastructure metadata services.

Successful exploitation of this vulnerability can lead to the exposure of sensitive internal data, such as cloud environment credentials or configuration details hidden behind the firewall. By leveraging the application server as a proxy, an attacker can bypass network perimeters to interact with internal services that are not exposed to the public internet, potentially leading to further system compromise. The CVSS score of 7.7 reflects the high impact on internal confidentiality and the ability to pivot deeper into the network.

Immediate Action: Upgrade to Open Notebook version 1.11.0 or later immediately to incorporate the required URL validation logic.

Proactive Monitoring: Monitor application logs for suspicious POST requests to the /api/sources endpoint that contain internal IP addresses or sensitive URI schemes in the URL parameter.

Compensating Controls: Deploy a Web Application Firewall (WAF) or egress filtering rules to restrict the application server from initiating connections to internal subnets or restricted cloud metadata IP addresses (e.g., 169.254.169.254).

Public Exploit Available: Unknown

The vulnerability presents a significant risk to the integrity of internal network services. Organizations utilizing Open Notebook must prioritize upgrading to version 1.11.0 to address the underlying validation flaw. Until the update is applied, administrative teams should ensure that the application environment is isolated from sensitive internal services via restrictive egress filtering.