CVE-2019-8836 in tvOS
Summary
by MITRE • 10/28/2020
A memory corruption issue was addressed with improved memory handling. This issue is fixed in watchOS 6.1.2, iOS 13.3.1 and iPadOS 13.3.1, tvOS 13.3.1. An application may be able to execute arbitrary code with kernel privileges.
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Analysis
by VulDB Data Team • 11/29/2020
The vulnerability identified as CVE-2019-8836 represents a critical memory corruption flaw that existed within Apple's operating systems including watchOS, iOS, iPadOS, and tvOS. This issue stems from inadequate memory handling mechanisms that could potentially allow malicious applications to escalate privileges and execute arbitrary code with kernel-level access. The vulnerability affects multiple Apple platforms simultaneously, indicating a systemic flaw in the memory management subsystem that requires comprehensive remediation across all affected operating systems. The memory corruption aspect of this vulnerability aligns with CWE-122, which describes improper handling of memory allocation and deallocation that can lead to buffer overflows and related security issues.
The technical nature of this flaw involves improper memory management that creates opportunities for attackers to manipulate memory structures and potentially bypass security boundaries. When an application can execute arbitrary code with kernel privileges, it essentially gains complete control over the device's operating system and all its resources. This type of privilege escalation vulnerability represents a severe threat to device security and user privacy. The flaw likely involves memory corruption during application execution or system processes that could be exploited through carefully crafted inputs or malicious applications designed to trigger the memory handling error.
The operational impact of CVE-2019-8836 extends far beyond typical application-level security issues, as it enables attackers to achieve root-level access to affected devices. This vulnerability could potentially allow for complete device compromise, data exfiltration, persistent backdoor installation, and unauthorized access to sensitive user information. The fact that this issue affects multiple Apple platforms simultaneously suggests that the underlying memory management flaw exists in shared system components that are common across these operating systems. Such vulnerabilities are particularly dangerous because they can be exploited through legitimate applications that may appear harmless to users, making detection and prevention more challenging for security professionals.
Apple addressed this vulnerability through comprehensive updates released as watchOS 6.1.2, iOS 13.3.1, and iPadOS 13.3.1, along with tvOS 13.3.1. The fix involved improved memory handling mechanisms that prevent the conditions necessary for memory corruption to occur. Organizations and users should prioritize immediate deployment of these security updates to mitigate the risk of exploitation. Security teams should implement monitoring for potential exploitation attempts and consider the vulnerability in their threat modeling activities, particularly focusing on the ATT&CK framework's privilege escalation techniques. The mitigation strategy should include not only patch deployment but also network monitoring for suspicious activities that might indicate exploitation attempts, as well as user education about the risks of installing untrusted applications that could potentially trigger such memory corruption vulnerabilities.