CVE-2021-30773

From The Apple Wiki

In July 2021 (2021-07), Apple released iOS 14.7, and the security notes mention:

Identity Service
Available for: iPhone 6s and later, iPad Pro (all models), iPad Air 2 and later, iPad 5th generation and later, iPad mini 4 and later, and iPod touch (7th generation)
Impact: A malicious application may be able to bypass code signing checks
Description: An issue in code signature validation was addressed with improved checks.
CVE-2021-30773: Linus Henze (pinauten.de)

Diffing 14.6 and 14.7 shows no changes in IDS frameworks, and the only change in the identityservicesd daemon is in IDSIDStatusQueryController, methods _loadCache and _saveCache. This seems unlikely to be related to "code signature validation".

It turns out the bug is only present in arm64e, which is why diffing arm64 binaries didn't find anything...

This vulnerability is apparently used in Fugu14. [1]