Introduction
Remote code execution through a single malicious website is a risk for any unpatched Apple device running outdated versions of macOS Ventura, iOS, iPadOS, or Safari. In July 2023, Apple addressed a critical use after free vulnerability in WebKit (CVE-2023-43000) that could allow attackers to corrupt memory and potentially execute arbitrary code simply by processing crafted web content.
Apple is one of the most widely recognized technology companies globally, with hundreds of millions of active devices running its operating systems. WebKit, the browser engine at the heart of Safari and many Apple apps, is a core component for web content rendering on all Apple platforms. Vulnerabilities in WebKit have broad implications due to its integration across macOS, iOS, and iPadOS.
Technical Information
CVE-2023-43000 is a use after free vulnerability (CWE-416) in the WebKit rendering engine. The flaw occurs when memory is freed but still referenced by the application, which can lead to memory corruption. In this specific case, the vulnerability could be triggered by processing specially crafted web content. Attackers could exploit this by luring users to a malicious website or injecting malicious content into a trusted site. Successful exploitation could result in arbitrary code execution within the context of the affected application, such as Safari or any app using WebKit for rendering.
Apple's advisory notes that the issue was addressed with improved memory management. No public code snippets or detailed code-level disclosures are available for this vulnerability. The root cause is improper handling of object lifecycles in WebKit, leading to a scenario where freed memory is accessed again, violating memory safety.
Affected Systems and Versions
- macOS Ventura versions prior to 13.5
- iOS versions prior to 16.6
- iPadOS versions prior to 16.6
- Safari versions prior to 16.6 (on macOS Big Sur and macOS Monterey)
Any configuration using these versions is vulnerable if WebKit processes untrusted web content.
Vendor Security History
Apple has a recurring history of memory safety issues in WebKit, with multiple use after free and memory corruption vulnerabilities patched in recent years. The company typically responds with coordinated security updates across all supported platforms. Apple publishes advisories and releases patches promptly, but the complexity of WebKit continues to make it a frequent target for security research and exploitation.
