Wait. Correction for accuracy: The iPhone 4s actually patched the original limera1n exploit used on the iPhone 4. But in 2017, axi0mX discovered —a permanent, unpatchable bootrom exploit for all A5 through A11 chips. The 4s (A5 chip) is vulnerable to checkm8. This changes everything. The Two Paths to iOS 5 Path 1: The "Time Capsule" Method (Requires Saved Blobs) If you were a meticulous jailbreaker in 2012 and saved your SHSH blobs for iOS 5.0.1 or 5.1.1 using TinyUmbrella or Cydia, you are in luck.
Enter or N1ghtshade (from the developer dora2ios). downgrade iphone 4s to ios 5
However, the 4s has one fatal hardware flaw—or savior, depending on your perspective—that later iPhones lack: . The 4s (A5 chip) is vulnerable to checkm8
But is it possible? The answer is The Core Problem: APTicket and Signing The iPhone 4s introduced a major security hurdle: the APTicket (or SHSH blob). Unlike the iPhone 4 (which had a hardware exploit allowing permanent downgrades), the 4s uses a chain of trust that requires Apple’s signature for each restore. Without a saved SHSH blob from the time iOS 5 was being signed , a standard downgrade is impossible. Enter or N1ghtshade (from the developer dora2ios)