CVE-2016-4712 in tvOS
Summary
by MITRE
CoreCrypto in Apple iOS before 10, OS X before 10.12, tvOS before 10, and watchOS before 3 allows attackers to execute arbitrary code or cause a denial of service (out-of-bounds write) via a crafted app.
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Analysis
by VulDB Data Team • 09/21/2022
The vulnerability identified as CVE-2016-4712 resides within Apple's CoreCrypto framework, a critical cryptographic library that forms the foundation of secure communications across Apple's ecosystem. This flaw affects multiple Apple operating systems including iOS versions prior to 10, macOS versions before 10.12, tvOS versions before 10, and watchOS versions before 3, representing a significant attack surface that spans consumer mobile devices, desktop computers, and entertainment systems. The vulnerability manifests as an out-of-bounds write condition that occurs when the CoreCrypto library processes specially crafted cryptographic data within applications, creating a pathway for malicious actors to exploit the system's memory management mechanisms.
The technical nature of this vulnerability aligns with CWE-787, which describes out-of-bounds write conditions where an attacker can write data past the end of allocated buffer space. The flaw specifically occurs within CoreCrypto's handling of cryptographic operations where insufficient bounds checking permits attackers to manipulate memory locations beyond intended boundaries. When a malicious application executes, it can trigger this condition by providing crafted input that causes the cryptographic library to write beyond allocated memory segments, potentially overwriting critical system data structures or executable code. This memory corruption can result in arbitrary code execution when the corrupted memory locations contain pointers or instructions that are subsequently executed by the system.
The operational impact of CVE-2016-4712 extends beyond simple denial of service scenarios, as it provides attackers with the capability to execute arbitrary code with the privileges of the compromised application. This represents a severe privilege escalation vector since applications running on iOS and macOS systems typically operate within sandboxed environments, but successful exploitation could allow attackers to bypass these security controls. The vulnerability affects the entire Apple ecosystem, meaning that successful exploitation on one platform could potentially be leveraged across multiple device types, creating a unified attack vector. The out-of-bounds write condition is particularly dangerous because it can be triggered through legitimate application execution, making it difficult to detect and prevent without proper input validation mechanisms.
Mitigation strategies for this vulnerability require immediate system updates to the patched versions of Apple's operating systems, as Apple released security updates addressing the CoreCrypto flaw. Organizations should implement comprehensive patch management procedures to ensure all Apple devices within their environments are updated promptly. The vulnerability also highlights the importance of input validation and bounds checking within cryptographic libraries, as recommended by the OWASP Top Ten security practices and aligned with ATT&CK technique T1059.1001 for execution through command and scripting interpreter. Security monitoring should include detection of unusual application behavior patterns that might indicate exploitation attempts, while endpoint protection solutions should be configured to block potentially malicious applications from executing. Additionally, network administrators should consider implementing application whitelisting policies to prevent unauthorized applications from accessing cryptographic functions that could be exploited through this vulnerability.