Apache Storm Webapp is vulnerable to multiple cross-origin information disclosure flaws that allow unauthorized entities to read sensitive data on behalf of an authenticated operator.

The application fails to properly validate origins and enforces insecure Cross-Origin Resource Sharing (CORS) configurations, alongside an unconfigurable JSONP implementation, which allows a malicious site to bypass same-origin protections and extract data accessible to an authenticated user.

Successful exploitation leads to the unauthorized disclosure of sensitive cluster configurations, topology details, and internal logs. Given the CVSS score of 8.1, this represents a high-severity risk as it directly facilitates information theft, which could be used by an attacker to map the internal network or identify further vulnerabilities within the Apache Storm environment.

Immediate Action: Upgrade Apache Storm Webapp to version 3.1.0 or later to resolve the CORS misconfigurations and provide the ability to disable JSONP.

Proactive Monitoring: Review web server and application access logs for unusual requests containing callback parameters or requests originating from unexpected domains that attempt to access UI, Logviewer, or DRPC endpoints.

Compensating Controls: If an immediate update is not feasible, place the affected HTTP endpoints behind a reverse proxy configured to strip Access-Control-Allow-Origin and Access-Control-Allow-Credentials headers and reject any requests containing a callback parameter.

Public Exploit Available: No

The vulnerabilities identified in Apache Storm Webapp pose a significant risk to data confidentiality for any organization relying on the platform for cluster management. It is critical that administrators prioritize the update to version 3.1.0 to ensure these security gaps are closed. Where patching is delayed, the suggested reverse proxy configuration should be implemented as a mandatory interim security measure to protect against cross-origin data theft.