CVE-2016-4736 in macOS
Summary
by MITRE
libarchive in Apple OS X before 10.12 allows remote attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact via a crafted file.
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Analysis
by VulDB Data Team • 09/06/2024
The vulnerability identified as CVE-2016-4736 affects libarchive, a widely used library for handling various archive formats within Apple's operating systems. This library serves as the foundation for numerous applications including Archive Utility, which handles common archive formats such as tar, zip, and various compression formats. The flaw exists in versions of Apple OS X prior to 10.12, making a substantial user base susceptible to potential exploitation. The vulnerability stems from improper handling of malformed archive files during the extraction or parsing process, creating a memory corruption condition that can be triggered remotely through maliciously crafted archive content.
Technical exploitation of this vulnerability involves crafting a specially designed archive file that, when processed by libarchive, triggers memory corruption within the library's parsing routines. The flaw manifests as heap-based buffer overflows or use-after-free conditions when the library attempts to parse malformed metadata or compressed data structures within the archive. According to CWE classification, this vulnerability maps to CWE-125, which describes out-of-bounds read conditions, and CWE-476, which covers null pointer dereference scenarios. The memory corruption can potentially lead to arbitrary code execution or system instability, depending on the specific nature of the heap corruption and the execution environment where the vulnerability is triggered.
The operational impact of CVE-2016-4736 extends beyond simple denial of service scenarios, as the memory corruption could potentially be leveraged for more sophisticated attacks. Attackers could exploit this vulnerability by delivering malicious archive files through various attack vectors including email attachments, malicious websites, or compromised software distributions. The vulnerability's remote exploitation capability means that users could be compromised simply by opening or processing an archive file, without requiring any special privileges or user interaction beyond the normal archive extraction process. This makes it particularly dangerous in enterprise environments where automatic archive extraction might occur, or where users frequently download and process files from untrusted sources.
Mitigation strategies for CVE-2016-4736 primarily involve upgrading to Apple OS X version 10.12 or later, where the vulnerability has been addressed through improved input validation and memory management within libarchive. System administrators should implement strict file validation policies, particularly for archive files received from external sources, and consider deploying sandboxing mechanisms to limit the potential impact of exploitation. Network-based mitigations could include implementing content filtering solutions that scan archive files for known malicious patterns or using network segmentation to limit exposure. The vulnerability also highlights the importance of regular security updates and proper patch management, as it demonstrates how seemingly benign library functions can contain critical security flaws that affect entire operating system ecosystems. Organizations should also consider implementing security monitoring solutions that can detect anomalous behavior patterns associated with memory corruption exploits, particularly in systems that process large volumes of archive files from external sources.