We’ve noticed that many iOS developers received warnings (as cited below) from Apple on March 8. We’d love to know which actions may cause such warnings. And will these actions cause app rejection or removal?
Runtime methods like respondsToSelector:, performSelector:, method_exchangeImplementations, class_replaceMethod and class_addMethod are all provided by Apple, which are largely used in many current apps and third-party libraries. Is the calling of the above methods allowed by Apple? Is there any possibility that our app may be removed from App Store or got rejected by App Review because of using them?
Thanks in advance.
Ref: The warning mail we saw online
Your app, extension, and/or linked framework appears to contain code designed explicitly with the capability to change your app’s behavior or functionality after App Review approval, which is not in compliance with section 3.3.2 of the Apple Developer Program License Agreement and App Store Review Guideline 2.5.2. This code, combined with a remote resource, can facilitate significant changes to your app’s behavior compared to when it was initially reviewed for the App Store. While you may not be using this functionality currently, it has the potential to load private frameworks, private methods, and enable future feature changes.
This includes any code which passes arbitrary parameters to dynamic methods such as dlopen(), dlsym(), respondsToSelector:, performSelector:, method_exchangeImplementations(), and running remote scripts in order to change app behavior or call SPI, based on the contents of the downloaded script. Even if the remote resource is not intentionally malicious, it could easily be hijacked via a Man In The Middle (MiTM) attack, which can pose a serious security vulnerability to users of your app.
Please perform an in-depth review of your app and remove any code, frameworks, or SDKs that fall in line with the functionality described above before submitting the next update for your app for review.
App Store Review