CVE-2016-1758 in iOS
Summary
by MITRE
The kernel in Apple iOS before 9.3 and OS X before 10.11.4 allows attackers to obtain sensitive memory-layout information or cause a denial of service (out-of-bounds read) via a crafted app.
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Analysis
by VulDB Data Team • 11/11/2024
The vulnerability identified as CVE-2016-1758 represents a critical memory safety issue affecting Apple's kernel implementation across iOS versions prior to 9.3 and OS X versions prior to 10.11.4. This flaw resides within the kernel's memory management subsystem and demonstrates the classic characteristics of an out-of-bounds read condition that can be exploited by malicious applications to extract sensitive information from kernel memory spaces. The vulnerability operates at the core level of Apple's operating systems, where kernel memory layout information can be accessed through improper bounds checking during memory operations.
The technical implementation of this vulnerability stems from inadequate validation of memory access boundaries within kernel functions responsible for processing memory requests from user-space applications. When a crafted application submits malicious input to kernel memory operations, the system fails to properly validate buffer limits, resulting in memory reads that extend beyond allocated boundaries. This condition allows attackers to access adjacent memory locations containing sensitive kernel data structures, configuration information, or other confidential data that should remain protected from user-space access. The vulnerability specifically manifests as an out-of-bounds read operation that can be leveraged for information disclosure rather than direct code execution, though the information obtained can be extremely valuable for subsequent exploitation attempts.
The operational impact of CVE-2016-1758 extends beyond simple information disclosure to potentially enable more sophisticated attacks within the Apple ecosystem. Attackers can utilize the leaked memory layout information to bypass kernel memory protection mechanisms such as address space layout randomization, which relies on unpredictable memory addresses for security. This vulnerability directly violates the fundamental security principle of kernel isolation and can be classified under CWE-129 as an improper input validation issue. The ability to obtain memory layout information provides attackers with critical intelligence for crafting more effective exploits, potentially leading to privilege escalation or complete system compromise. The vulnerability affects all Apple devices running the affected operating system versions, making it particularly dangerous as it impacts a broad user base.
Mitigation strategies for this vulnerability require immediate system updates to the patched versions of iOS 9.3 and OS X 10.11.4, which include proper bounds checking mechanisms and memory validation routines. System administrators and users should prioritize updating their devices to prevent exploitation, as the vulnerability can be exploited without user interaction through malicious applications. The fix implemented by Apple addresses the root cause by strengthening kernel memory access controls and implementing additional validation checks for memory operations. Organizations should also consider implementing application whitelisting policies to prevent installation of untrusted applications that might attempt to exploit this vulnerability. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and information gathering, specifically covering the T1068 privilege escalation tactic and T1082 system information discovery technique. The vulnerability demonstrates the importance of kernel-level security controls and proper memory management practices in preventing information disclosure attacks that can undermine system security.