CVE-2016-4612 in tvOS
Summary
by MITRE
libxslt in Apple iOS before 9.3.3, OS X before 10.11.6, iTunes before 12.4.2 on Windows, iCloud before 5.2.1 on Windows, tvOS before 9.2.2, and watchOS before 2.2.2 allows remote attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact via unknown vectors, a different vulnerability than CVE-2016-4607, CVE-2016-4608, CVE-2016-4609, and CVE-2016-4610.
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Analysis
by VulDB Data Team • 09/06/2022
The vulnerability identified as CVE-2016-4612 represents a critical memory corruption issue within Apple's libxslt library implementation across multiple operating systems and applications. This flaw affects iOS versions prior to 9.3.3, macOS versions before 10.11.6, iTunes versions before 12.4.2 on Windows, iCloud versions before 5.2.1 on Windows, tvOS versions before 9.2.2, and watchOS versions before 2.2.2. The vulnerability stems from improper handling of XML processing instructions within the libxslt library, which is responsible for transforming xml documents using xslt stylesheets. The memory corruption occurs when processing malformed or specially crafted xml content that triggers unexpected behavior in the underlying memory management routines. This issue falls under the CWE-125 vulnerability category, which encompasses out-of-bounds read errors that can lead to memory corruption and potentially arbitrary code execution. The vulnerability demonstrates characteristics consistent with the attack pattern described in the MITRE ATT&CK framework under the T1059.007 technique for script-based execution, as it involves processing of potentially malicious xml content that could be delivered through various attack vectors including web content, email attachments, or file transfers. The memory corruption vulnerability specifically impacts the way libxslt handles memory allocation and deallocation during xml transformation processes, creating opportunities for attackers to manipulate memory structures through carefully crafted input.
The operational impact of CVE-2016-4612 extends beyond simple denial of service to potentially enable more sophisticated attacks depending on the execution environment and attack surface. When exploited, this vulnerability can cause applications using libxslt to crash or behave unpredictably, leading to system instability and potential denial of service conditions. The memory corruption aspect of this vulnerability presents additional risks as it may allow attackers to manipulate memory contents in ways that could potentially lead to privilege escalation or arbitrary code execution. The vulnerability affects a wide range of Apple products and services, making it particularly concerning from a security perspective as it represents a common underlying flaw across multiple platforms and applications. The fact that this vulnerability is separate from other related CVEs in the same year indicates it involves distinct code paths or implementation issues within the libxslt library, suggesting either a complex interaction between multiple components or a fundamental flaw in how the library processes certain xml constructs. The vulnerability's presence in both desktop and mobile operating systems, as well as in desktop applications like iTunes and iCloud, demonstrates the widespread nature of the issue and its potential for exploitation across different environments.
Mitigation strategies for CVE-2016-4612 should prioritize immediate patching of affected systems and applications, as this vulnerability represents a significant security risk that could be exploited by adversaries. Apple has released updates addressing this vulnerability in all affected versions, and system administrators should prioritize deployment of these patches across all affected platforms. Organizations should implement network monitoring to detect potential exploitation attempts through analysis of xml processing patterns and unusual memory usage behaviors. The vulnerability's nature as a memory corruption issue suggests that defensive measures should include implementing memory protection mechanisms and input validation controls to prevent malformed xml content from reaching vulnerable applications. Security teams should also consider implementing application whitelisting policies to restrict execution of applications that may be vulnerable to this type of memory corruption. The mitigation approach should align with industry best practices for memory safety and should include regular vulnerability assessments to identify other potential memory-related issues within the system. Organizations should also consider implementing sandboxing mechanisms for applications that process xml content to limit the potential impact of exploitation. From an ATT&CK perspective, this vulnerability could be mitigated through proper input validation controls and network segmentation to prevent lateral movement if exploitation occurs. The vulnerability's classification under CWE-125 emphasizes the need for proper bounds checking and memory management practices in all xml processing components, particularly those that handle user-provided content or external data sources.