CVE-2015-5938 in Mac OS X
Summary
by MITRE
ImageIO in Apple OS X before 10.11.1 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via crafted metadata in an image.
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Analysis
by VulDB Data Team • 11/19/2024
The vulnerability identified as CVE-2015-5938 represents a critical security flaw within Apple's ImageIO framework affecting macOS versions prior to 10.11.1. This issue stems from insufficient validation of image metadata structures, creating a pathway for remote attackers to exploit memory corruption vulnerabilities through maliciously crafted image files. The flaw exists in the way the system processes image metadata, particularly when handling malformed or specially constructed metadata fields that trigger unexpected behavior in the underlying memory management systems.
The technical implementation of this vulnerability involves the ImageIO framework's failure to properly sanitize metadata entries within image files, particularly when processing formats such as jpeg, png, and tiff. Attackers can construct image files containing malformed metadata sequences that, when processed by the system, cause memory corruption through buffer overflows or improper memory deallocation. The vulnerability specifically targets the memory management routines within the ImageIO framework, where the system attempts to parse and interpret metadata without adequate bounds checking or input validation. This flaw operates at the intersection of multiple security domains including memory safety, input validation, and image processing protocols.
From an operational perspective, this vulnerability presents significant risks to macOS users and organizations as it enables remote code execution capabilities without requiring user interaction or elevated privileges. The attack vector can be delivered through various channels including web browsing, email attachments, or file sharing systems where users might unknowingly open malicious image files. The potential impact extends beyond simple code execution to include complete system compromise, as successful exploitation can lead to arbitrary code execution with the privileges of the affected process. This vulnerability particularly affects systems running macOS versions 10.10.5 and earlier, making them susceptible to exploitation by threat actors targeting Apple platforms.
The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds writes, both of which are common patterns in memory corruption vulnerabilities. From the ATT&CK framework perspective, this vulnerability maps to techniques involving execution through image processing, specifically T1064 and T1059, where adversaries leverage legitimate system components to execute malicious code. The exploitation process typically involves crafting a malicious image file with specially designed metadata that triggers the vulnerable code path when the system attempts to display or process the image. This attack methodology demonstrates how seemingly benign functionality can be weaponized to achieve system compromise.
Mitigation strategies for CVE-2015-5938 primarily focus on immediate system updates to macOS 10.11.1 or later versions, which contain patches addressing the memory corruption issues in ImageIO. Organizations should implement comprehensive patch management policies to ensure all systems receive timely security updates. Additional protective measures include deploying web application firewalls, implementing strict file validation policies for image uploads, and utilizing sandboxing techniques to limit potential damage from successful exploitation attempts. Security monitoring should include detection of unusual image processing activities and potential attempts to exploit this vulnerability through network traffic analysis. System administrators should also consider implementing automated scanning tools to identify and quarantine potentially malicious image files within their networks.