Overview
- Independent observer Aaron Perris posted the change on X Thursday, and Mac-focused sites quickly reported that Apple had stopped validating certain baseband builds tied to old iOS releases.
- The company removed server-side signatures for baseband (cellular modem) firmware rather than pulling signatures for the iOS images themselves.
- Affected models are cellular variants only and include decade-old devices such as the CDMA iPhone 4, iPhone 4S, iPhone 5/5c, and cellular iPad 2/3/4 and the original iPad mini.
- The practical effect is users cannot restore or install the listed builds by OTA or by using IPSW files through Finder or iTunes, while devices already running current firmware continue to operate.
- 9to5Mac later reported that signing for the listed versions was briefly resumed, and coverage notes the move was narrow in scope and reached only a tiny user base with old cellular hardware.