CVE-2020-9928 in macOS
Summary
by MITRE • 10/23/2020
Multiple memory corruption issues were addressed with improved memory handling. This issue is fixed in macOS Catalina 10.15.6. An application may be able to execute arbitrary code with kernel privileges.
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Analysis
by VulDB Data Team • 11/26/2020
The vulnerability identified as CVE-2020-9928 represents a critical memory corruption issue that affects macOS systems, specifically impacting the kernel's memory management mechanisms. This flaw stems from inadequate memory handling practices that create opportunities for malicious code execution with elevated privileges. The vulnerability was remediated in macOS Catalina version 10.15.6, indicating that the underlying memory corruption patterns were addressed through improved kernel memory management protocols. The security implications of this issue extend beyond typical application-level exploits, as successful exploitation can grant attackers kernel-level privileges, fundamentally compromising system integrity and security boundaries.
The technical nature of CVE-2020-9928 aligns with common memory corruption vulnerabilities that fall under CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write conditions. These memory corruption patterns typically arise from insufficient bounds checking during memory allocation and deallocation processes within kernel space. The flaw likely manifests through improper handling of memory buffers, where applications or malicious code can manipulate memory structures to execute arbitrary code with the highest system privileges. Such vulnerabilities often exploit race conditions or improper validation of input parameters that are processed by kernel-level memory management functions.
The operational impact of this vulnerability is severe given that successful exploitation enables attackers to execute arbitrary code with kernel privileges, effectively bypassing all user-mode security controls and protections. This privilege escalation capability allows threat actors to gain complete control over affected systems, potentially leading to data exfiltration, persistence mechanisms establishment, or further network reconnaissance activities. The vulnerability's exploitation requires an application running on the target system to initiate the malicious code execution, making it particularly concerning for environments where users may inadvertently execute malicious software or where applications with elevated privileges are present. The kernel-level execution capability also means that traditional endpoint protection mechanisms may be bypassed entirely.
Mitigation strategies for CVE-2020-9928 primarily focus on timely system updates and maintaining current macOS versions to ensure the patched memory handling mechanisms are in place. System administrators should prioritize deployment of macOS Catalina 10.15.6 or later versions across all affected endpoints to address the memory corruption issues. Additional defensive measures include implementing application whitelisting policies to limit execution of untrusted code, monitoring for unusual kernel-level activity, and maintaining comprehensive system monitoring to detect potential exploitation attempts. The vulnerability's classification under the ATT&CK framework would likely map to privilege escalation techniques, specifically T1068 which covers exploit for privilege escalation, and potentially T1543 which addresses create or modify system process. Organizations should also consider implementing network segmentation and access controls to limit potential lateral movement if exploitation occurs, while maintaining regular security assessments to identify similar memory corruption vulnerabilities in other system components.