CVE-2022-26717 - Use-After-Free Vulnerability in Webkit Allows Arbitrary Code Execution, Resolved With Improved Memory Management

A recently discovered vulnerability, CVE-2022-26717, involves a use-after-free issue that was addressed through improved memory management. This security flaw has been fixed in various Apple operating system updates including tvOS 15.5, watchOS 8.6, iOS 15.5 and iPadOS 15.5, macOS Monterey 12.4, Safari 15.5, and iTunes 12.12.4 for Windows. The vulnerability can be exploited by processing maliciously crafted web content, which may lead to arbitrary code execution. In this post, we will discuss the details of this vulnerability, how it can be exploited, and the measures taken to mitigate it.

Details

The CVE-2022-26717 vulnerability exists in Webkit, Apple's open-source web content rendering engine used across its products. The vulnerability stems from a use-after-free issue in WebKit, which can be exploited by an attacker to execute arbitrary code on the target machine. A use-after-free vulnerability occurs when an application continues to use a memory location after it has been freed. This can lead to crashes, data corruption, or, in more severe cases, arbitrary code execution.

Exploit Details

In the case of CVE-2022-26717, an attacker could craft malicious web content designed to trigger the use-after-free vulnerability. By enticing the user to visit a website containing the malicious content, as the user navigates through the site, it could potentially lead to remote code execution of the attacker's choice on the victim's device. To better understand the issue, let's look at a simplified code snippet that could trigger this vulnerability:

function triggerVulnerability() {
    let obj = document.createElement('div');
    let anotherObj = obj.cloneNode();

    obj.outerHTML = ''; // Free the memory
    anotherObj.innerHTML = 'Exploit Code, PoC or Payload'; // Use-after-free
}

The above code snippet demonstrates the basic idea behind the exploitation process for this vulnerability. While the actual exploit might be more complex, this serves as a starting point to illustrate the issue.

Mitigation

Apple has addressed this vulnerability with improved memory management in its recent updates. The following list details the fixed versions for various Apple operating systems:

iTunes 12.12.4 for Windows

If you are using any of the affected products, it is highly recommended that you update to the latest versions as soon as possible to protect your devices from this vulnerability. Updating your software ensures that you are running the most secure versions available, protecting your system and data from threats and exploits.

To learn more about CVE-2022-26717, you can refer to the official sources below

- Apple's official security advisory
- National Vulnerability Database entry

Conclusion

CVE-2022-26717 is a use-after-free vulnerability in Apple's Webkit that could potentially allow an attacker to execute arbitrary code on a victim's device by processing maliciously crafted web content. It is crucial to update your operating software to its latest version on all your Apple devices to prevent the exploitation of this vulnerability. Stay informed about new security flaws and keep your software up-to-date to ensure your devices' safety and security.

Timeline

Published on: 11/01/2022 20:15:00 UTC
Last modified on: 11/03/2022 13:14:00 UTC