CVE-2016-4682 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.12 is affected. macOS before 10.12.1 is affected. The issue involves the "ImageIO" component. It allows remote attackers to obtain sensitive information or cause a denial of service (out-of-bounds read and application crash) via a crafted SGI file.
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Analysis
by VulDB Data Team • 09/28/2022
The vulnerability identified as CVE-2016-4682 represents a critical security flaw within Apple's macOS operating system affecting versions prior to 10.12 and specifically impacting macOS versions before 10.12.1. This issue resides within the ImageIO component, which serves as a core framework responsible for handling various image file formats and processing image data within Apple's ecosystem. The ImageIO framework is extensively utilized across macOS applications and system components, making this vulnerability particularly concerning as it could potentially be exploited across multiple attack vectors.
The technical nature of this vulnerability stems from improper input validation within the SGI (Silicon Graphics Image) file parser implementation. When processing a specially crafted SGI image file, the ImageIO component fails to properly validate array bounds during the parsing process, resulting in out-of-bounds read conditions. This flaw manifests as a memory access violation that occurs when the parser attempts to read data beyond the allocated memory boundaries of the image file structure. The vulnerability is classified under CWE-125 as an out-of-bounds read, which represents a common class of memory safety issues that can lead to information disclosure or system instability.
The operational impact of CVE-2016-4682 extends beyond simple denial of service scenarios, as it provides attackers with the capability to potentially extract sensitive information from system memory. Remote attackers could leverage this vulnerability by delivering a maliciously crafted SGI file through various attack vectors such as email attachments, web downloads, or malicious websites. Upon successful exploitation, the vulnerability could trigger application crashes or, more critically, allow information disclosure attacks where attackers might gain access to sensitive memory contents including kernel data, application memory, or user credentials that happen to be stored in adjacent memory regions. This makes the vulnerability particularly dangerous in environments where macOS systems process untrusted image content from external sources.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation, as it provides an initial foothold for attackers to potentially escalate their privileges or access additional system resources. The vulnerability's remote exploitability means that attackers do not require physical access to the target system, making it particularly attractive for large-scale attacks. Organizations running affected macOS versions should prioritize immediate patching and implement network-based controls such as email filtering and web proxy restrictions to prevent the delivery of malicious SGI files. Additionally, system administrators should consider implementing application whitelisting policies that restrict the execution of image processing applications with elevated privileges when handling untrusted content, thereby reducing the attack surface and potential impact of exploitation attempts.