CVE-2019-8536 in iCloud
Summary
by MITRE
A memory corruption issue was addressed with improved memory handling. This issue is fixed in iOS 12.2, tvOS 12.2, watchOS 5.2, Safari 12.1, iTunes 12.9.4 for Windows, iCloud for Windows 7.11. Processing maliciously crafted web content may lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 08/08/2023
The vulnerability identified as CVE-2019-8536 represents a critical memory corruption flaw that affected multiple Apple operating systems and applications. This issue stems from inadequate memory handling mechanisms within Apple's software ecosystem, specifically impacting iOS 12.2, tvOS 12.2, watchOS 5.2, Safari 12.1, iTunes 12.9.4 for Windows, and iCloud for Windows 7.11. The vulnerability manifests when processing maliciously crafted web content, creating a pathway for attackers to achieve arbitrary code execution on affected systems. The memory corruption occurs during the parsing and rendering of web content, where improper memory management allows attackers to manipulate memory layout and potentially overwrite critical system structures.
The technical nature of this vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which addresses buffer overflow vulnerabilities in heap-based memory allocations. These classifications indicate that the flaw occurs in heap memory management where insufficient bounds checking allows attackers to write beyond allocated memory regions. The vulnerability operates through a classic memory corruption attack vector where malicious web content is crafted to trigger specific memory allocation patterns that result in controlled memory overwrite. The attack requires no user interaction beyond visiting a malicious website or opening a specially crafted web page, making it particularly dangerous as it can be exploited through drive-by downloads or malicious advertisements.
From an operational perspective, the impact of CVE-2019-8536 extends across Apple's entire ecosystem, affecting mobile devices, desktop applications, and web browsers simultaneously. The arbitrary code execution capability provides attackers with complete system compromise, potentially enabling data theft, persistent backdoor installation, or further escalation attacks. This vulnerability particularly affects enterprise environments where users may visit untrusted websites or receive malicious email attachments containing compromised web content. The attack surface is broad due to the inclusion of Safari 12.1, which means that web-based attacks could target users across different device types, from iPhones and iPads to Mac computers running the affected versions. The vulnerability's exploitation potential is further enhanced by its ability to function through standard web browsing activities, making it difficult to defend against through traditional network monitoring approaches.
The mitigation strategy for CVE-2019-8536 primarily involves immediate deployment of Apple's security patches, which were released as part of iOS 12.2, tvOS 12.2, watchOS 5.2, Safari 12.1, iTunes 12.9.4 for Windows, and iCloud for Windows 7.11 updates. Organizations should prioritize patch management and ensure all affected systems receive these updates promptly. Additionally, network administrators should implement web filtering solutions and content inspection systems that can detect and block malicious web content before it reaches end-user systems. The vulnerability's characteristics make it particularly susceptible to defense-in-depth approaches, where multiple layers of security controls work together to prevent exploitation. Security teams should also monitor for indicators of compromise related to this vulnerability, including unusual network connections or file modifications that might indicate successful exploitation attempts. Organizations should consider implementing browser hardening measures, such as disabling unnecessary browser features and restricting access to potentially malicious websites through corporate firewalls and proxy servers. The remediation process should include comprehensive testing of patches in controlled environments before widespread deployment to ensure compatibility with existing enterprise applications and systems.