CVE-2017-2420 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.12.4 is affected. The issue involves the "Bluetooth" component. It 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 • 11/15/2022
The vulnerability identified as CVE-2017-2420 represents a critical security flaw within Apple's macOS operating system affecting versions prior to 10.12.4. This issue specifically targets the Bluetooth component of the system, which serves as a fundamental communication interface for wireless device connectivity. The vulnerability stems from improper input validation and memory handling within the Bluetooth stack, creating a pathway for malicious actors to exploit system resources. The flaw operates at a low level within the kernel space, where Bluetooth services interact with core operating system functions, making it particularly dangerous as it can be leveraged to gain elevated privileges.
The technical exploitation of this vulnerability occurs through a crafted application that manipulates Bluetooth communication protocols in ways that trigger memory corruption within the system's Bluetooth subsystem. When the malicious application is executed, it can cause the Bluetooth driver to process malformed data structures that lead to memory allocation errors and potential code execution. This memory corruption vulnerability falls under the CWE-121 category of "Stack-based Buffer Overflow" and potentially CWE-787 "Out-of-bounds Write" as the attacker can manipulate memory locations beyond the intended buffer boundaries. The attack vector requires local execution of a malicious application, but the impact extends far beyond simple local privilege escalation, as successful exploitation can enable attackers to execute arbitrary code with kernel-level privileges.
From an operational perspective, this vulnerability presents significant risk to macOS users as it allows attackers to bypass standard security mechanisms that typically protect against unauthorized code execution. The ability to execute code in a privileged context means that an attacker who successfully exploits this vulnerability can gain complete control over the affected system, potentially leading to data theft, persistent backdoor installation, or further network compromise. The denial of service aspect of this vulnerability can also be leveraged to disrupt critical system functions, particularly in environments where Bluetooth connectivity is essential for device operation or security protocols. This vulnerability aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1068 for "Exploitation for Privilege Escalation" within the enterprise attack framework, as it enables attackers to move laterally and establish persistent access through kernel-level privileges.
The mitigation strategy for CVE-2017-2420 involves immediate deployment of Apple's security updates, specifically macOS 10.12.4 and subsequent versions that contain patches addressing the Bluetooth memory corruption issue. Organizations should implement comprehensive patch management protocols to ensure all affected systems receive updates promptly, as the vulnerability can be exploited remotely if Bluetooth is enabled and connected to malicious devices. System administrators should also consider implementing network segmentation and Bluetooth device access controls to reduce the attack surface, particularly in enterprise environments where multiple Bluetooth devices may be in proximity. Additionally, monitoring for suspicious Bluetooth connection patterns and unexpected system behavior can help detect potential exploitation attempts, while regular security assessments should verify that all systems have been properly updated to prevent this vulnerability from being used as an initial access vector in broader attack campaigns.