Shopify App: Token exchange shop context confusion may allow cross-shop authorization bypass in affected apps

[ Description ]Official description

Shopify App is a Rails engine for building Shopify applications. From 22.1.0 until 23.0.3, `token-exchange` authenticated controllers can expose a request-derived `shop` context instead of the identity from a verified Shopify ID token or active Shopify session. `current_shopify_domain` can resolve to the sanitized `shop` query parameter, so a request authenticated for one `shop` can cause application code to treat a different requested `shop` as current. Affected applications use `shopify_app` `token-exchange` authentication, accept authenticated requests with a `shop` query parameter, and rely on `current_shopify_domain` or `params[:shop]` for authorization, tenant lookup, stored access-token selection or `shop`-scoped data access. An attacker with a valid Shopify session token for one `shop` can supply another `shop` in that parameter and potentially obtain unauthorized application data or perform `shop`-scoped actions, depending on the application's authorization model. This issue is fixed in version 23.0.3.

[ Fixes ]Fixes and patches

• shopify_app 23.0.3Fixed version · GitHub Advisories · rubygems package shopify_app: upgrade to 23.0.3 or later (affected >= 22.1.0, < 23.0.3)

[ Packages ]Affected open-source packages

• shopify_app rubygemsAffected >= 22.1.0, < 23.0.3 · fixed in 23.0.3 · GHSA-6j52-38f8-qhxr

[ References ]References

• github.com/Shopify/shopify_app/commit/a09ccc04b9556cbb31c6d56ed81aeb6b9b6c0756
• github.com/Shopify/shopify_app/pull/2081
• github.com/Shopify/shopify_app/releases/tag/v23.0.3
• github.com/Shopify/shopify_app/security/advisories/GHSA-6j52-38f8-qhxr