CVE-2023-40403 in macOS
Summary
by MITRE • 09/27/2023
The issue was addressed with improved memory handling. This issue is fixed in macOS Ventura 13.6, tvOS 17, iOS 16.7 and iPadOS 16.7, macOS Monterey 12.7, watchOS 10, iOS 17 and iPadOS 17, macOS Sonoma 14. Processing web content may disclose sensitive information.
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Analysis
by VulDB Data Team • 01/20/2026
This vulnerability represents a memory handling flaw that emerged in Apple's operating systems, specifically affecting versions prior to the mentioned security updates. The issue stems from inadequate memory management during web content processing operations, creating potential pathways for information disclosure. The vulnerability was addressed through enhanced memory handling mechanisms that prevent improper memory access patterns during web rendering and content processing. The fix demonstrates Apple's ongoing efforts to strengthen memory safety controls in their software ecosystems.
The technical implementation of this vulnerability involves improper memory allocation and deallocation practices during web content processing operations. When the system processes web content, it encounters scenarios where memory regions may be accessed beyond their intended boundaries or where sensitive data remains accessible in memory locations that should have been cleared. This memory handling deficiency creates opportunities for attackers to potentially extract sensitive information through memory inspection techniques. The flaw likely manifests in how the system manages memory pools during web rendering, particularly when handling complex web pages with dynamic content or embedded resources. This type of vulnerability falls under the category of memory safety issues commonly classified as CWE-125, which describes out-of-bounds read conditions.
The operational impact of this vulnerability extends across multiple Apple platforms including iOS, iPadOS, macOS, watchOS, and tvOS, indicating a widespread concern within the company's ecosystem. Attackers could potentially exploit this weakness to gain unauthorized access to sensitive information that was processed through web browsers or web-based applications. The disclosure of sensitive information could include user data, session tokens, or other confidential content that was temporarily stored in memory during web processing operations. The vulnerability represents a significant concern for users who frequently engage with web content, as it could enable persistent information leakage across different device types and operating system versions.
The security implications of this vulnerability align with the broader ATT&CK framework's information gathering tactics, where adversaries seek to extract sensitive data from compromised systems. This particular flaw could be leveraged in combination with other attack vectors to create more sophisticated exploitation scenarios. The memory handling improvements implemented in the security updates address the root cause by enforcing stricter memory boundary checks and implementing more robust memory cleanup procedures. These mitigations help prevent the type of memory corruption that could lead to information disclosure during web content processing. The fix demonstrates Apple's proactive approach to addressing memory safety vulnerabilities through comprehensive system-level improvements rather than patching individual applications.
Organizations and users should prioritize immediate deployment of the security updates across all affected platforms to mitigate potential exploitation risks. The vulnerability's presence across multiple operating system versions underscores the importance of maintaining current security patches and updates. System administrators should monitor for successful patch deployment and verify that all endpoints have received the necessary security improvements. The memory handling enhancements included in these updates provide defense-in-depth measures that help protect against similar vulnerabilities that might be discovered in the future. Regular security assessments should include memory safety reviews to identify potential issues before they can be exploited by malicious actors.