CVE-2018-4248 in macOS
Summary
by MITRE
An out-of-bounds read was addressed with improved input validation. This issue affected versions prior to iOS 11.4.1, macOS High Sierra 10.13.6, tvOS 11.4.1, watchOS 4.3.2.
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Analysis
by VulDB Data Team • 03/01/2020
The vulnerability identified as CVE-2018-4248 represents a critical out-of-bounds read flaw that was discovered in Apple's operating systems. This type of vulnerability falls under the category of memory safety issues and specifically manifests as an improper input validation problem that allows attackers to read memory locations outside the bounds of allocated buffers. The flaw existed in multiple Apple platforms including iOS, macOS, tvOS, and watchOS, indicating a widespread impact across the company's ecosystem. The vulnerability was particularly concerning because it could potentially be exploited to execute arbitrary code or cause system instability, making it a significant security concern for users of affected versions.
The technical nature of this out-of-bounds read vulnerability stems from insufficient validation of user inputs or data processing within Apple's system components. When applications or system services process data without proper boundary checks, they may attempt to access memory regions that have not been allocated for their use. This typically occurs in scenarios involving buffer operations, string handling, or array processing where the code assumes certain data lengths or structures without verifying these assumptions. The vulnerability allows an attacker to craft malicious inputs that trigger the out-of-bounds memory access, potentially leading to information disclosure, system crashes, or more severe exploitation outcomes. This issue is classified as a CWE-129 weakness, which specifically addresses insufficient input validation, and represents a common vector for privilege escalation attacks within the ATT&CK framework under the technique of privilege escalation through memory corruption.
The operational impact of CVE-2018-4248 was substantial across Apple's user base, as it affected versions of the operating systems prior to the release of iOS 11.4.1, macOS High Sierra 10.13.6, tvOS 11.4.1, and watchOS 4.3.2. Users running these vulnerable versions faced increased risk of system compromise, particularly in environments where the affected software was used for sensitive operations or contained confidential data. The vulnerability's presence in multiple platforms meant that organizations with mixed device environments needed to prioritize patching across all affected operating systems. The impact extended beyond individual users to enterprise environments where Apple devices were used for business-critical applications, potentially exposing sensitive corporate data or disrupting operational continuity. Security professionals noted that the vulnerability could be particularly dangerous when combined with other exploits, as the out-of-bounds read could be leveraged to gain information about system memory layout, which would facilitate more sophisticated attacks. Organizations needed to implement immediate patch management strategies and consider the potential for zero-day exploitation of this vulnerability in the wild.
Mitigation strategies for CVE-2018-4248 centered primarily on updating to the patched versions of the affected operating systems. Apple released updates that included improved input validation mechanisms to prevent the out-of-bounds read conditions that led to the vulnerability. System administrators and users were advised to immediately install the security updates available through the respective operating system update mechanisms. The patching process involved implementing stricter buffer boundary checks and input validation routines within the affected system components. Organizations should have also considered implementing additional security monitoring to detect potential exploitation attempts and established incident response procedures to handle any suspected compromise. The vulnerability highlighted the importance of maintaining up-to-date systems and demonstrated how memory safety issues could have widespread implications across multiple platforms. Security teams were encouraged to perform vulnerability assessments to identify any remaining systems that might not have been updated, as the out-of-bounds read could potentially be exploited in targeted attacks against specific user groups or organizations with slower update cycles. This vulnerability reinforced industry best practices regarding input validation and memory safety in software development, emphasizing the need for comprehensive testing and security reviews of system components before deployment.