CVE-2016-7580 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.12 is affected. The issue involves the "Mail" component, which allows remote web servers to cause a denial of service via a crafted URL.
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Analysis
by VulDB Data Team • 08/16/2020
The vulnerability identified as CVE-2016-7580 represents a significant security flaw within Apple's macOS Mail application affecting versions prior to 10.12. This issue demonstrates how seemingly benign web interactions can be exploited to create substantial operational disruptions. The vulnerability specifically resides within the mail component's handling of crafted URLs, which can be manipulated by remote web servers to trigger unexpected behavior in the application. The flaw operates at the intersection of web protocol handling and application memory management, creating a pathway for malicious actors to exploit the system through standard internet communication channels.
The technical implementation of this vulnerability involves the Mail application's insufficient validation of URL structures when processing web content. When a user opens an email containing a maliciously crafted URL, the application's parser fails to properly handle the malformed input, leading to memory corruption or resource exhaustion. This behavior manifests as an application crash or complete system hang, effectively creating a denial of service condition that prevents legitimate email access. The vulnerability falls under CWE-121, which addresses stack-based buffer overflow conditions, and more specifically aligns with CWE-122, heap-based buffer overflow, as the memory management issues occur during URL parsing operations. The attack vector requires minimal user interaction, typically involving the simple act of opening an email message containing the malicious payload, making it particularly dangerous in enterprise environments where users may inadvertently trigger the exploit.
From an operational standpoint, this vulnerability presents substantial risk to organizations relying on Apple mail clients for business communication. The denial of service impact can disrupt critical email workflows, potentially affecting business continuity and communication channels. The remote nature of the attack means that adversaries can exploit the vulnerability without requiring physical access to target systems or user credentials. Security professionals should consider this vulnerability in relation to ATT&CK technique T1499.004, which covers network denial of service attacks, as the exploitation creates network-level disruption through application-level vulnerabilities. The vulnerability's impact extends beyond simple service interruption, as it can be used as a stepping stone for more sophisticated attacks or as part of larger campaign strategies targeting Apple users.
Organizations should prioritize immediate remediation through macOS updates to version 10.12 or later, where Apple has implemented proper URL validation and memory handling mechanisms. System administrators should also consider implementing email filtering solutions that can identify and quarantine suspicious URL patterns before they reach end users. Network monitoring solutions should be configured to detect unusual patterns of application crashes or service interruptions that may indicate exploitation attempts. Additionally, user education programs should emphasize the importance of not opening emails from untrusted sources and the potential risks associated with clicking on embedded links. The vulnerability highlights the critical importance of keeping software updated and maintaining robust security practices, particularly for applications that handle internet content and user interactions. Organizations should also consider implementing sandboxing techniques for email applications and monitoring for anomalous memory usage patterns that may indicate exploitation attempts.