CVE-2019-8573 in watchOS
Summary
by MITRE • 10/28/2020
An input validation issue was addressed with improved input validation. This issue is fixed in macOS Mojave 10.14.5, Security Update 2019-003 High Sierra, Security Update 2019-003 Sierra, iOS 12.3, watchOS 5.2.1. A remote attacker may be able to cause a system denial of service.
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Analysis
by VulDB Data Team • 11/27/2020
The vulnerability identified as CVE-2019-8573 represents a critical input validation flaw that affected multiple Apple operating systems including macOS Mojave, iOS, and watchOS. This issue stems from insufficient validation of user-supplied input data, creating potential pathways for malicious actors to exploit system stability. The vulnerability was particularly concerning as it could be leveraged by remote attackers to trigger system denial of service conditions, effectively disrupting normal operations and potentially affecting numerous users simultaneously.
The technical nature of this flaw aligns with common software security weaknesses documented in CWE-20, which addresses "Improper Input Validation" as a fundamental category of security vulnerabilities. This classification indicates that the underlying issue involves inadequate sanitization or validation of data inputs that could be manipulated by external parties to cause unintended behavior. The vulnerability specifically affected Apple's operating systems through their handling of certain input streams that should have been properly validated before processing, allowing attackers to craft malicious inputs that could cause system instability or complete system crashes.
From an operational perspective, this vulnerability posed significant risks to enterprise and individual users alike, as remote exploitation could lead to widespread service disruption. The affected systems included macOS versions 10.14.5 and earlier, as well as iOS 12.3 and watchOS 5.2.1, indicating a broad attack surface that required immediate attention. The denial of service condition could manifest in various ways including system crashes, application hangs, or complete system restarts, all of which would impact user productivity and system availability. Organizations relying on these platforms faced potential operational disruptions that could affect business continuity and user experience.
The remediation approach for CVE-2019-8573 involved implementing enhanced input validation mechanisms across the affected Apple platforms. Apple addressed this issue through security updates that included improved sanitization of input data and strengthened validation routines to prevent malicious inputs from causing system instability. The fixes were rolled out as part of comprehensive security updates for macOS High Sierra, macOS Sierra, iOS 12.3, and watchOS 5.2.1, demonstrating Apple's commitment to addressing security vulnerabilities in their ecosystem. Organizations should have implemented these updates promptly to ensure protection against potential exploitation. The mitigation strategy also aligns with ATT&CK framework techniques related to system exploitation and privilege escalation, where input validation flaws represent common attack vectors that adversaries leverage to compromise system integrity and availability.
Security professionals should consider this vulnerability as part of broader input validation testing procedures and implement regular security assessments to identify similar weaknesses in their environments. The remediation process demonstrates the importance of maintaining up-to-date security patches and the critical nature of input validation in preventing exploitation of system vulnerabilities. Organizations should also consider implementing network monitoring and intrusion detection systems to identify potential exploitation attempts of similar vulnerabilities in their infrastructure.