CVE-2017-13800 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.13.1 is affected. The issue involves the "APFS" component. It allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app.
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Analysis
by VulDB Data Team • 01/05/2023
The vulnerability identified as CVE-2017-13800 represents a critical security flaw within Apple's Apple File System implementation that affected macOS versions prior to 10.13.1. This issue resides within the APFS (Apple File System) component which serves as the primary storage architecture for Apple devices including Mac computers, iPhones, and iPads. The vulnerability stems from improper handling of memory structures within the file system's kernel extension, creating a pathway for malicious actors to exploit memory corruption vulnerabilities. The flaw specifically manifests when the system processes crafted applications that contain malformed data structures designed to trigger buffer overflows or other memory manipulation techniques. Security researchers have classified this vulnerability under CWE-121, which describes "Stack-based Buffer Overflow" conditions that occur when a program writes beyond the boundaries of a fixed-length buffer, and potentially CWE-125, which covers "Out-of-bounds Read" scenarios where programs access memory locations beyond the allocated buffer boundaries. The attack vector requires an attacker to have the ability to install and execute a malicious application on the target system, making it particularly concerning in environments where users may inadvertently download compromised software or where privilege escalation attacks are possible. The vulnerability's impact extends beyond simple code execution to include potential denial of service conditions that could crash the system or render it unstable. According to MITRE ATT&CK framework, this vulnerability aligns with techniques such as T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, as the attacker can leverage the memory corruption to gain elevated privileges. The APFS implementation's kernel-level operation means that successful exploitation could allow attackers to execute arbitrary code with root privileges, effectively compromising the entire system. This vulnerability represents a fundamental flaw in how Apple's file system handles memory management during application processing, creating a persistent threat vector that could be exploited by sophisticated attackers. The issue highlights the critical importance of kernel-level security in modern operating systems where memory corruption vulnerabilities can provide direct pathways to system compromise.
The technical exploitation of CVE-2017-13800 occurs when a malicious application is executed that contains specifically crafted data structures designed to trigger memory corruption within the APFS kernel extension. The vulnerability exploits the way the file system handles metadata processing and buffer management, particularly when encountering malformed or specially constructed file system structures. Attackers can manipulate the APFS implementation to cause stack-based buffer overflows or heap corruption that allows them to overwrite critical memory locations. The exploitation process typically involves creating a malicious application that, when executed, triggers the vulnerable code path within the APFS kernel component. This could occur through various means including malicious software installation, compromised applications from untrusted sources, or even social engineering attacks that trick users into executing the malicious payload. The memory corruption can manifest as either arbitrary code execution or denial of service conditions that crash the system. The vulnerability's exploitation is particularly concerning because it operates at the kernel level, meaning that successful exploitation could grant attackers complete control over the system. The APFS implementation's design flaws create predictable memory access patterns that attackers can leverage to achieve their objectives. This vulnerability demonstrates the inherent risks of complex kernel-level code where memory management errors can have catastrophic consequences for system security.
The operational impact of CVE-2017-13800 extends far beyond simple privilege escalation or denial of service scenarios, as it represents a fundamental weakness in Apple's core storage architecture that could enable comprehensive system compromise. Organizations and individual users running affected macOS versions face significant risk of unauthorized access, data theft, and system instability. The vulnerability's potential for arbitrary code execution makes it particularly dangerous in enterprise environments where a single compromised device could serve as a foothold for broader network attacks. The memory corruption nature of the vulnerability means that attackers could potentially use it to install persistent backdoors, exfiltrate sensitive data, or disrupt critical operations. System administrators must consider the implications for security monitoring and incident response, as exploitation of this vulnerability could occur without traditional signs of compromise. The vulnerability's presence in the file system kernel component means that even legitimate applications could potentially trigger the exploit if they contain malformed data structures. This makes the vulnerability particularly difficult to detect and prevent through conventional security measures. The widespread adoption of macOS in enterprise environments means that this vulnerability could impact numerous systems simultaneously, creating a significant security risk for organizations that rely on Apple's ecosystem. The vulnerability's exploitation could also enable attackers to bypass security controls that depend on the integrity of the file system, potentially undermining the effectiveness of various security mechanisms.
Mitigation strategies for CVE-2017-13800 focus primarily on updating to macOS 10.13.1 or later versions where Apple has implemented patches addressing the memory corruption issues within the APFS implementation. Organizations should prioritize immediate deployment of the security update to protect their systems from exploitation. System administrators should also implement additional security controls including application whitelisting, sandboxing, and monitoring for unusual system behavior that could indicate exploitation attempts. The vulnerability's kernel-level nature means that traditional endpoint protection solutions may not provide adequate protection, requiring more comprehensive security approaches including system integrity monitoring and behavioral analysis. Network administrators should consider implementing network-based detection measures to identify potential exploitation attempts, as attackers may attempt to establish command and control communications after successful exploitation. Regular security assessments should include verification of system patch levels and monitoring for signs of memory corruption or unauthorized system modifications. Organizations should also implement strict application control policies to prevent execution of untrusted applications that could potentially trigger the vulnerability. The mitigation process should include comprehensive testing of updates in controlled environments before widespread deployment to ensure compatibility with existing applications and systems. Security teams should develop incident response procedures specifically addressing this vulnerability, including forensic analysis capabilities to investigate potential exploitation attempts and recovery procedures for compromised systems. Given the nature of the vulnerability, organizations should also consider implementing additional layers of security including regular system integrity checks, monitoring for unauthorized kernel module loading, and maintaining detailed system logs for forensic analysis.