Impact An unsanitized input of Next.js SDK tunnel endpoint allows sending HTTP requests to arbitrary URLs and reflecting the response back to the user. This could open door for other attack vectors: client-side vulnerabilities: XSS/CSRF in the context of the trusted domain; interaction with internal network; read cloud metadata endpoints (AWS, Azure, Google Cloud, etc.); local/remote port scan.

This issue only affects users who have Next.js SDK tunneling feature enabled.

Patches The problem has been fixed in sentry/nextjs@7.77.0

Workarounds Disable tunneling by removing the tunnelRoute option from Sentry Next.js SDK config — next.config.js or next.config.mjs.

References Sentry Next.js tunneling feature The fix More Information

Credits Praveen Kumar

Sentry SDK is the official Python SDK for Sentry, real-time crash reporting software. When using the Django integration of versions prior to 1.14.0 of the Sentry SDK in a specific configuration it is possible to leak sensitive cookies values, including the session cookie to Sentry. These sensitive cookies could then be used by someone with access to your Sentry issues to impersonate or escalate their privileges within your application.

In order for these sensitive values to be leaked, the Sentry SDK configuration must have sendDefaultPII set to True; one must use a custom name for either SESSIONCOOKIENAME or CSRFCOOKIENAME in one's Django settings; and one must not be configured in one's organization or project settings to use Sentry's data scrubbing features to account for the custom cookie names.

As of version 1.14.0, the Django integration of the sentry-sdk will detect the custom cookie names based on one's Django settings and will remove the values from the payload before sending the data to Sentry. As a workaround, use the SDK's filtering mechanism to remove the cookies from the payload that is sent to Sentry. For error events, this can be done with the beforesend callback method and for performance related events (transactions) one can use the beforesendtransaction callback method. Those who want to handle filtering of these values on the server-side can also use Sentry's advanced data scrubbing feature to account for the custom cookie names. Look for the $http.cookies, $http.headers, $request.cookies, or $request.headers fields to target with a scrubbing rule.