CVE-2017-2548 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.12.5 is affected. The issue involves the "WindowServer" 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 • 09/02/2024
The vulnerability identified as CVE-2017-2548 represents a critical security flaw within Apple's macOS operating system affecting versions prior to 10.12.5. This issue resides within the WindowServer component which serves as the core graphical subsystem responsible for managing window operations, display rendering, and user interface elements. The WindowServer process operates with elevated privileges to ensure proper system graphics handling and user interaction management. Attackers can exploit this vulnerability through a specially crafted application that triggers memory corruption within the WindowServer process, potentially leading to arbitrary code execution in a privileged context or system-wide denial of service conditions.
The technical nature of this vulnerability stems from improper input validation and memory management within the WindowServer component. When processing maliciously crafted applications, the system fails to properly validate graphical input parameters, leading to buffer overflows or memory corruption conditions that can be leveraged by attackers. This flaw operates at the kernel-level graphics subsystem, making it particularly dangerous as it can be exploited without requiring user interaction beyond launching the malicious application. The vulnerability maps to CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of how graphics rendering components can become attack vectors due to insufficient bounds checking and memory management practices.
The operational impact of CVE-2017-2548 extends beyond simple privilege escalation as it provides attackers with a pathway to gain unauthorized system access through the graphics subsystem. Once exploited, the vulnerability allows attackers to execute arbitrary code with the privileges of the WindowServer process, which typically runs with system-level permissions. This capability enables attackers to install malware, modify system files, or establish persistent backdoors within the affected macOS installations. The vulnerability also presents a significant denial of service risk, as memory corruption can cause the WindowServer process to crash, resulting in complete system instability and requiring manual restart to restore normal operations. Organizations running affected macOS versions face substantial risk of unauthorized access and system compromise through this vector.
Mitigation strategies for CVE-2017-2548 primarily focus on immediate system updates and administrative controls. Apple released macOS 10.12.5 as a direct patch addressing this vulnerability, which should be deployed immediately across all affected systems. System administrators should implement strict application whitelisting policies to prevent execution of untrusted applications that could exploit this vulnerability. Network segmentation and monitoring should be enhanced to detect potential exploitation attempts through suspicious graphical application launches. The vulnerability aligns with ATT&CK technique T1059 which covers command and scripting interpreter usage, as attackers may leverage the privilege escalation to execute malicious code through the compromised graphics subsystem. Additionally, implementing sandboxing controls for graphics-intensive applications and monitoring for unusual WindowServer process behavior can provide additional layers of protection against exploitation attempts.