CVE-2019-19074 in Linux
Summary
by MITRE • 01/25/2023
A memory leak in the ath9k_wmi_cmd() function in drivers/net/wireless/ath/ath9k/wmi.c in the Linux kernel through 5.3.11 allows attackers to cause a denial of service (memory consumption), aka CID-728c1e2a05e4.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 02/23/2024
The vulnerability identified as CVE-2019-19074 represents a critical memory management flaw within the Linux kernel's wireless networking subsystem, specifically affecting the ath9k driver implementation. This issue resides in the ath9k_wmi_cmd() function located at drivers/net/wireless/ath/ath9k/wmi.c, where improper memory handling leads to persistent memory leaks that can be exploited by malicious actors. The vulnerability affects all Linux kernel versions up to and including 5.3.11, making it a widespread concern across numerous production systems that rely on wireless networking capabilities.
The technical root cause of this vulnerability stems from inadequate memory deallocation practices within the wireless management interface (WMI) command processing loop. When the ath9k_wmi_cmd() function handles wireless management commands, it fails to properly release allocated memory resources in certain error handling paths or command processing scenarios. This memory leak occurs incrementally with each WMI command execution, leading to progressive memory consumption that can eventually exhaust available system resources. The flaw operates at the kernel level, meaning that even legitimate wireless operations can contribute to memory degradation when repeated sufficiently.
From an operational perspective, this vulnerability enables attackers to perform a denial of service attack by repeatedly triggering WMI commands through malicious wireless packets or network traffic manipulation. The memory leak accumulation results in system instability, reduced performance, and ultimately complete system unresponsiveness or crash. Network administrators and security professionals should recognize this as a particularly dangerous vulnerability because it can be exploited remotely without requiring elevated privileges, and the effects are cumulative rather than immediate. The impact extends beyond simple service disruption to potentially compromising entire network infrastructure when multiple affected devices are present.
The vulnerability maps directly to CWE-401: "Improper Release of Memory Before Removing Last Reference" and aligns with ATT&CK technique T1499.001: "Endpoint Denial of Service" in its ability to consume system resources and render systems non-functional. Mitigation strategies include applying the latest kernel patches from the Linux kernel security team, which typically involve implementing proper memory deallocation in error handling paths. System administrators should also consider implementing network monitoring to detect unusual memory consumption patterns and establish memory pressure thresholds to trigger automated response mechanisms. Additionally, deploying network segmentation and access controls to limit wireless access points can reduce the attack surface, while regular kernel updates and security audits form the foundation of comprehensive defense against such memory-related vulnerabilities.