CVE-2018-4434 in macOS
Summary
by MITRE
An out-of-bounds read was addressed with improved input validation. This issue affected versions prior to macOS Mojave 10.14.2.
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Analysis
by VulDB Data Team • 04/18/2020
The vulnerability identified as CVE-2018-4434 represents a critical out-of-bounds read flaw that existed in Apple's macOS operating system prior to the release of version 10.14.2. This type of vulnerability falls under the broader category of memory safety issues and is particularly dangerous because it can potentially allow attackers to read data from memory locations that should not be accessible. The flaw was specifically addressed through enhanced input validation mechanisms implemented by Apple in their security updates. The issue affected multiple versions of macOS including High Sierra and Sierra, making it a widespread concern for users running older operating system releases.
The technical nature of this vulnerability stems from improper bounds checking during the processing of user-supplied input or system data structures. When applications or system components attempt to access memory locations beyond their allocated boundaries, an out-of-bounds read can occur, potentially exposing sensitive information stored in adjacent memory regions. This particular flaw was classified under CWE-129 as an Improper Validation of Array Index, which is a well-known weakness in software security that directly relates to inadequate input validation. The vulnerability could be exploited by malicious actors who might craft specific inputs designed to trigger the out-of-bounds memory access, potentially leading to information disclosure or further exploitation.
From an operational impact perspective, this vulnerability posed significant risks to macOS users and organizations relying on older system versions. The out-of-bounds read could potentially expose kernel memory contents, user credentials, or other sensitive data that might otherwise remain protected. Attackers could leverage this flaw to gain insights into system memory structures, potentially enabling more sophisticated attacks such as privilege escalation or information gathering. The vulnerability's impact was particularly concerning given that it affected the core operating system components that handle various system functions and user interactions. This aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, as exploitation might involve crafting inputs to trigger the memory access violation, and T1003.001 for OS Credential Dumping if sensitive information is accessed.
The remediation for CVE-2018-4434 was implemented through Apple's security updates that introduced enhanced input validation mechanisms to prevent the out-of-bounds memory access conditions. Users running macOS versions prior to 10.14.2 were strongly advised to install the latest security patches immediately to protect against potential exploitation. Organizations implementing security controls should have prioritized patch management for this vulnerability, as it represented a significant risk to system integrity and data confidentiality. The fix demonstrated Apple's commitment to addressing memory safety vulnerabilities through proactive security measures and input validation improvements. Security professionals should have monitored the vulnerability's status through official channels and ensured that all affected systems were updated to prevent potential exploitation attempts. The resolution of this vulnerability highlights the importance of maintaining up-to-date operating system versions and implementing robust patch management processes to protect against known security flaws.