Frontend: integration setup wizard navigates to an unvalidated redirect_uri (open redirect and javascript: execution) #15303

Summary

The integration setup wizard navigates to the redirect_uri query parameter verbatim on Continue and Cancel, with no scheme, host or registered-URI check. A crafted link can send a signed-in user to any external site (open redirect), and a javascript: value runs script in the platform's origin.

Affected code

• autogpt_platform/frontend/src/app/(platform)/auth/integrations/setup-wizard/page.tsx:99 (redirectURI = searchParams.get("redirect_uri"))
• .../setup-wizard/page.tsx:151 (handleComplete: window.location.href = `${redirectURI}?${params.toString()}` ) and :167 (handleCancel, same pattern)
• The page already fetches the OAuth app (useGetOauthGetOauthAppInfo(clientID), line 102) but only for display; nothing compares redirect_uri to the app's registered URIs. client_id is also optional.

This is the same class as #15047/#15048 (and PR #15057), but those and the PR only cover /auth/authorize (authorize/page.tsx); the setup wizard is a separate page and is not touched by that PR.

Trigger / steps to reproduce

1. While signed in (the page is behind the protected /auth/integrations prefix), open /auth/integrations/setup-wizard?providers=<base64 of [{"provider":"github"}]>&redirect_uri=https://evil.example/phish&state=x.
2. Click "Cancel" (always enabled; "Continue" works once providers are connected).
3. The browser navigates to https://evil.example/phish?error=user_cancelled&error_description=...&state=x.
   For script execution use redirect_uri=javascript:<code>//; the code builds javascript:<code>//?error=user_cancelled&... and the trailing query becomes a JS comment.

Expected vs actual

Expected: only the client's registered redirect URIs (or at least same-origin / http(s) URLs) are navigated to; anything else shows an error.
Actual: any string is assigned to window.location.href.

Severity

Medium. A trusted-domain page that can be turned into a phishing redirect with one click and, through javascript:, into script execution with the victim's session. It needs the victim to open a crafted link and click a button.

How confirmed

Read the page. Reproduced the exact navigation pattern in a local browser page (http://localhost): a button doing window.location.href = `${redirectURI}?${params.toString()}` with redirect_uri=javascript:document.title='js-ran:'+location.origin// executed the script in the page origin (the page text became js-ran:http://localhost:8765). I did not run the full platform stack, so the setup-wizard page itself was not exercised end to end.

Fix feasibility

Yes: validate redirectURI with the same safety helper being added for the authorize page (redirect-safety.ts in PR #15057) and check it against the app's registered URIs before navigating.