CVE-2016-1808 in iOS
Summary
by MITRE
The Disk Images subsystem in Apple iOS before 9.3.2, OS X before 10.11.5, tvOS before 9.2.1, and watchOS before 2.2.1 allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app.
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Analysis
by VulDB Data Team • 11/04/2024
The vulnerability identified as CVE-2016-1808 resides within Apple's Disk Images subsystem, a critical component responsible for handling disk image files across multiple Apple operating systems. This subsystem processes various file formats including dmg, iso, and other disk image types that users might encounter when mounting external storage devices, downloading software packages, or installing applications. The flaw affects a broad range of Apple platforms including iOS versions prior to 9.3.2, macOS versions before 10.11.5, tvOS versions before 9.2.1, and watchOS versions before 2.2.1, indicating a widespread impact across Apple's ecosystem. The vulnerability stems from insufficient input validation and memory handling within the disk image processing logic, creating a condition where maliciously crafted disk image files can trigger unexpected behavior in the underlying system.
Technical exploitation of this vulnerability occurs through the manipulation of disk image file structures that are processed by the Disk Images subsystem. When a user opens or mounts a specially crafted disk image file, the subsystem fails to properly validate the file's contents, leading to memory corruption that can be leveraged to execute arbitrary code with elevated privileges. The flaw represents a classic buffer overflow or memory corruption vulnerability that allows attackers to manipulate the execution flow of the privileged processes handling disk image operations. This type of vulnerability is categorized under CWE-125 as "Out-of-bounds Read" and potentially CWE-787 as "Out-of-bounds Write" depending on the specific memory corruption pattern. The attack vector requires user interaction through the opening of a malicious disk image, making it a sandbox escape vulnerability that can bypass normal application security boundaries.
The operational impact of CVE-2016-1808 is severe and multifaceted, as it provides attackers with the ability to execute arbitrary code in a privileged context with system-level access. This capability enables complete system compromise, allowing adversaries to install malicious software, exfiltrate sensitive data, modify system configurations, or establish persistent backdoors. The vulnerability can be exploited remotely through various attack vectors including malicious email attachments, compromised websites, or infected software downloads that contain the malicious disk image files. The memory corruption aspect also presents a denial of service risk, where system stability may be compromised through controlled crashes or system hangs. From an adversary perspective, this vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, making it particularly dangerous in threat actor toolkits.
Mitigation strategies for CVE-2016-1808 primarily involve immediate system updates to the patched versions of Apple operating systems. Users should ensure their devices are updated to iOS 9.3.2, macOS 10.11.5, tvOS 9.2.1, and watchOS 2.2.1 or later versions where the vulnerability has been addressed. System administrators should implement comprehensive patch management policies to ensure all Apple devices within their network receive timely updates. Additional defensive measures include implementing strict file type validation for disk image files, disabling automatic mounting of external storage devices, and employing network-level filtering to block suspicious disk image file types. Security monitoring should focus on detecting unusual disk image processing activities and unauthorized privilege escalation attempts. The vulnerability demonstrates the importance of input validation and memory safety practices in system-level components, highlighting the need for robust security testing of core operating system subsystems that handle untrusted data.