CVE-2019-8817 in macOS
Summary
by MITRE
A validation issue was addressed with improved input sanitization. This issue is fixed in macOS Catalina 10.15.1. An application may be able to read restricted memory.
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Analysis
by VulDB Data Team • 01/31/2024
The vulnerability identified as CVE-2019-8817 represents a memory safety issue within Apple's macOS operating system that was resolved through enhanced input sanitization measures. This flaw existed in versions prior to macOS Catalina 10.15.1 and allowed for unauthorized memory access through improper validation of application inputs. The issue stems from insufficient sanitization of user-supplied data which could potentially be exploited to access restricted memory regions that should normally be protected from application-level access. The vulnerability demonstrates a classic memory corruption pattern where improper input handling creates opportunities for privilege escalation or information disclosure attacks.
The technical implementation of this vulnerability involves the operating system's failure to properly validate and sanitize inputs received from applications before processing them in memory operations. When applications submit data that is not adequately sanitized, the system's memory management functions may inadvertently expose restricted memory segments to unauthorized access. This type of vulnerability falls under the broader category of input validation flaws that are commonly catalogued under CWE-20, which specifically addresses "Improper Input Validation" in software security practices. The flaw represents a failure in the system's memory protection mechanisms, where the boundary checks between user-space applications and kernel-level memory segments become compromised due to inadequate sanitization routines.
The operational impact of CVE-2019-8817 extends beyond simple information disclosure, as it creates potential pathways for more sophisticated attacks that could leverage the unauthorized memory access to execute arbitrary code or escalate privileges. Attackers could potentially craft malicious inputs that, when processed by applications running on affected systems, would trigger the memory access violation and allow for data extraction from protected memory regions. This vulnerability particularly affects systems running macOS versions prior to 10.15.1 where the improved sanitization measures were implemented. The attack surface includes any application that processes user input without proper validation, making it a widespread concern across the macOS ecosystem. The vulnerability aligns with ATT&CK technique T1059 which covers "Command and Scripting Interpreter" and T1068 which addresses "Exploitation for Privilege Escalation" through memory corruption attacks.
Organizations and users should immediately update to macOS Catalina 10.15.1 or later versions to remediate this vulnerability, as the update includes the necessary input sanitization improvements that prevent the exploitation of this memory access flaw. System administrators should conduct comprehensive vulnerability assessments to identify any applications running on affected systems that may be susceptible to similar input validation issues, as the root cause of this vulnerability often indicates broader security gaps in application development practices. The fix implemented by Apple demonstrates proper security engineering principles through the implementation of robust input validation and sanitization routines that ensure all user-supplied data is properly checked before being processed in memory operations. Additionally, developers should adopt secure coding practices that emphasize input validation and memory safety to prevent similar vulnerabilities from being introduced in custom applications or third-party software running on macOS systems.