Iphone 4s Custom Firmware [better]

to iOS 6.1.3 or 8.4.1 without needing saved "SHSH blobs." It effectively creates a custom path to flash these older versions. CoolBooter

: Apple no longer "signs" older firmware, but specific exploits allow custom IPSW files to be flashed anyway. Dual Booting iphone 4s custom firmware

The iPhone 4s relies on the bootrom exploit (discovered by geohot in 2010) and the checkm8 exploit (axi0mX, 2019). Because these are hardware-level exploits (BootROM), Apple cannot patch them. to iOS 6