CVE-2016-4609 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-2016-4610, and CVE-2016-4612.
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Analysis
by VulDB Data Team • 09/06/2022
The vulnerability identified as CVE-2016-4609 represents a critical memory corruption issue within Apple's libxslt library implementation across multiple operating systems and applications. This flaw exists in various Apple products including 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 manifests as a remote code execution risk that can lead to denial of service conditions through memory corruption or potentially more severe unspecified impacts. The affected libxslt library is a crucial component for processing xml stylesheet transformations and is widely used throughout Apple's ecosystem for various applications including web content rendering and data processing. This vulnerability specifically impacts the XSLT (Extensible Stylesheet Language Transformations) processing capabilities that Apple employs in their software stack, making it a significant concern for system stability and security.
The technical exploitation of this vulnerability involves manipulating input data that gets processed through the libxslt library, leading to memory corruption patterns that can be leveraged by remote attackers to disrupt normal system operations. The flaw demonstrates characteristics consistent with heap-based buffer overflow conditions or use-after-free scenarios commonly found in C/C++ libraries that process untrusted input data. The vulnerability's classification as a memory corruption issue aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write vulnerabilities. Attackers can potentially craft malicious xml documents or stylesheet transformations that trigger the memory corruption when processed by affected Apple applications, leading to application crashes or system instability. The remote nature of this vulnerability means that attackers can exploit it without physical access to the target device, making it particularly dangerous in mobile and networked environments.
The operational impact of CVE-2016-4609 extends beyond simple denial of service scenarios to potentially enable more sophisticated attack vectors that could compromise system integrity and user data confidentiality. When applications crash due to memory corruption, they may leave systems in vulnerable states or provide opportunities for further exploitation. The widespread use of libxslt across Apple's product line means that a single vulnerability can affect numerous devices and applications simultaneously, creating substantial risk for enterprise and individual users alike. The vulnerability's presence in both desktop and mobile operating systems indicates that it affects Apple's cross-platform ecosystem, potentially allowing attackers to leverage a single attack vector against multiple device types. Organizations using Apple products in enterprise environments face significant risk from this vulnerability, as it could enable attackers to disrupt critical business operations or gain unauthorized access to sensitive information processed through affected applications.
Mitigation strategies for CVE-2016-4609 primarily focus on immediate software updates and patches provided by Apple to address the underlying memory corruption issue in the libxslt library. System administrators should prioritize updating all affected Apple products to their latest versions, including iOS 9.3.3 and later, macOS 10.11.6 and later, iTunes 12.4.2 and later, iCloud 5.2.1 and later, tvOS 9.2.2 and later, and watchOS 2.2.2 and later. Network monitoring solutions should be configured to detect unusual traffic patterns that might indicate exploitation attempts, particularly focusing on xml processing activities and stylesheet transformation requests. Security teams should implement application whitelisting policies to restrict execution of untrusted xml processing operations and consider network segmentation to limit potential lateral movement if exploitation occurs. The vulnerability's relationship to other CVEs including CVE-2016-4607, CVE-2016-4608, CVE-2016-4610, and CVE-2016-4612 indicates that Apple's libxslt implementation may contain multiple related memory corruption flaws, requiring comprehensive patch management across the entire affected product portfolio. Organizations should also consider implementing runtime protections and memory corruption detection mechanisms as additional defensive measures against similar vulnerabilities in their Apple-based systems.