CVE-2025-24200 - Inside the iOS & iPadOS USB Restricted Mode Bypass Exploit

In the world of iOS security, even tiny mistakes can turn into huge problems — especially when bad actors find clever ways to misuse them. CVE-2025-24200 is a real-world example where an authorization bug in iOS and iPadOS’s USB Restricted Mode created a path for attackers to physically bypass security, possibly putting sensitive data at risk. This post dives deep into what happened, how it worked, and how Apple fixed it.

What Is CVE-2025-24200?

CVE-2025-24200 is a vulnerability found in Apple's iOS and iPadOS operating systems in the way they handle the USB Restricted Mode. Normally, USB Restricted Mode is supposed to protect locked devices from USB-based attacks, such as those using GrayKey-like password cracking boxes. The flaw allowed someone with physical access to the device to disable this protection, potentially accessing private data.

What Is USB Restricted Mode, Anyway?

When an iPhone or iPad is locked, USB Restricted Mode blocks all USB accessories from connecting after an hour of inactivity. This is meant to stop data exfiltration and cracking tools. Here's Apple's own explanation:
About the USB Restricted Mode

How the Exploit Worked

The bug stemmed from state management issues. Put simply: the system didn’t handle certain physical state changes of the device correctly—which allowed a physically present attacker (think: a thief or state actor with your phone) to trick the device into thinking it was safe to enable USB again.

Attack Initiation: With a locked device, the attacker connects a rogue USB accessory.

2. Malicious State Manipulation: Through a sequence of physical actions (such as cycling power, using specific USB gadgets or adapters, or via glitching techniques), the attacker triggers a bug in the device's state logic.
3. Bypassing USB Restricted Mode: The device incorrectly believes the user has authenticated, and disables USB Restricted Mode.
4. Gaining Access: Now unprotected, the attacker connects tools designed to brute-force the device passcode or extract data via Lightning/USB.

Code Snippet: USB Restricted Mode Check (Illustrative Example)

Here’s a simplified pseudo-code of how a correct state check for USB Restricted Mode might look inside iOS:

// Pseudo-code for USB Restricted Mode state check
func usbAccessoryConnected() {
    if device.isLocked && !recentlyUnlocked() {
        // Stay in locked mode, deny USB access
        disableUSBPort()
    } else {
        // Allow normal USB accessory connection
        enableUSBPort()
    }
}

Prior to the patch, internal state flags could be manipulated mid-connection, confusing the logic above into allowing USB access even when the device was locked.

Exploit In Action: Real-World Targeting

Apple confirmed “Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals.”
That means attackers weren’t just playing around; they actually used this bug to go after high-value targets — possibly in government, business, or journalism.

Attackers use custom hardware (like special adapters or USB boxes) to manipulate USB state.

- After bypassing restrictions, they deploy password-cracking tools or extract data via forensics software, defeating Apple’s main physical security barrier.

Patch Details

Apple addressed CVE-2025-24200 by “improved state management”. This means the system now keeps better track of whether the device is truly unlocked before ever enabling USB accessories. The fix went into:

iPadOS 17.7.5 and 18.3.1

Official Apple Security Advisory:
About the security content of iOS 18.3.1 and iPadOS 18.3.1 - Apple Support

What Can You Do?

If you haven’t updated your iPhone or iPad, now’s the time! Once you’ve installed the patch, known physical attacks against USB Restricted Mode are foiled. For maximum security:

Set a strong passcode.

- Keep USB Accessories turned off while locked (Settings > Face/Touch ID & Passcode).

Why This Matters

CVE-2025-24200 shows that even “physical” security can have subtle software flaws. It’s another reminder that attackers—especially those targeting high-profile people—will hunt for every tiny gap.

References & Further Reading

- Apple Security Updates – iOS & iPadOS
- USB Restricted Mode Overview (Apple)
- Mitre CVE Entry – CVE-2025-24200
- Example research: GrayKey and Forensic USB Attacks

Timeline

Published on: 02/10/2025 19:15:40 UTC
Last modified on: 02/13/2025 16:24:24 UTC