In May 2022, Apple patched a significant security vulnerability known as CVE-2022-26714. This memory corruption issue affected multiple Apple platforms, including iOS, iPadOS, macOS, tvOS, and watchOS. Exploiting this flaw could let a malicious application execute arbitrary code with kernel privileges—a serious risk that could allow attackers to gain total control over your device.

This article breaks down what CVE-2022-26714 was all about, how attackers could weaponize it, and what Apple did to fix the bug. We'll use simple terms, share code snippets for illustration, and point you to official sources for further reading.

What Was CVE-2022-26714?

CVE-2022-26714 is a _memory corruption_ vulnerability in the kernel of Apple devices. The kernel is the core part of an operating system with the highest level of privileges. If an attacker can execute code in the kernel's context, they can bypass most security protections.

The vulnerability existed because the kernel didn’t properly validate certain inputs, which could corrupt memory in dangerous ways.

Spy on you by subverting security controls

The core issue was untrusted input leading to corruption in kernel memory, opening a door to taking over the system.

Note: This is for educational purposes only. Do not attempt to exploit any device.

While Apple keeps low-level details private, typical kernel memory corruption exploits on Apple platforms follow a pattern:

1. Find a Kernel Interface: Attackers look for a kernel service that handles user input (like IOKit).
2. Pass Crafted Data: They send input that bypasses validation. For example, passing a purposely malformed structure, or setting a field to an out-of-bounds value.
3. Trigger Memory Corruption: The kernel code fails to check the input correctly, leading to out-of-bounds writes, buffer overflows, or use-after-free conditions.
4. Achieve Arbitrary Code Execution: By overwriting function pointers or other sensitive parts of kernel memory, attackers redirect execution to their chosen code—now running as the most privileged user.

Example Exploit (Pseudocode)

While the exact CVE-2022-26714 exploit is not publicly released, similar bugs often involve sending unsafe input via IOKit interfaces.

Here's a simplified example

// Kernel method expecting a pointer and a size
IOReturn vulnerableMethod(uint64_t userPointer, size_t size) {
    // Missing: check if 'size' is sane or if 'userPointer' is in user space
    void *kernel_buffer = IOMalloc(size);
    // Vulnerability: user can provide a huge 'size' or invalid pointer
    copy_from_user(kernel_buffer, userPointer, size); // May corrupt kernel memory!
    // ... rest of code using corrupted data
    IOFree(kernel_buffer, size);
    return kIOReturnSuccess;
}

A malicious app could use IOConnectCallStructMethod or similar APIs to hit the vulnerable pathway. By giving a too-large size or tricky pointer, they would corrupt kernel memory.

How Apple Fixed It

Apple addressed CVE-2022-26714 by improving validation—that is, adding extra checks to ensure that user-supplied pointers and sizes are safe and sensible before touching kernel memory.

Fixed Code Snippet (Illustration)

// Now with validation!
IOReturn fixedMethod(uint64_t userPointer, size_t size) {
    if (size > MAX_ALLOWED_SIZE || !isUserAddress(userPointer)) {
        return kIOReturnBadArgument;
    }
    void *kernel_buffer = IOMalloc(size);
    if (!kernel_buffer) return kIOReturnNoMemory;
    if (copy_from_user(kernel_buffer, userPointer, size) != ) {
        IOFree(kernel_buffer, size);
        return kIOReturnError;
    }
    IOFree(kernel_buffer, size);
    return kIOReturnSuccess;
}

This extra validation stops memory corruption before it can start.

watchOS 8.6

Update your devices to stay protected. Out-of-date Apple devices are vulnerable.

- Apple Security Update CVE-2022-26714
- NIST NVD Entry for CVE-2022-26714
- Apple Security Releases (May 2022)

Relevant articles for further reading

- How Hackers Exploit Kernel Bugs
- A Guide to iOS Kernel Exploitation

Conclusion

CVE-2022-26714 was a critical bug that showed how tricky memory management in kernels can become a system-wide danger. Apple’s fix—improved validation—closed the gap, but only for users who keep their devices up to date!

If your Apple device is running any macOS, iOS, tvOS, or watchOS version released before May 2022, update now to stay safe.

Stay patched, stay safe.

> _This guide is exclusive and simplified for educational and awareness purposes. For security testing, always use your own devices and obey the law._

Timeline

Published on: 05/26/2022 19:15:00 UTC
Last modified on: 06/08/2022 00:33:00 UTC