CVE-2022-49405 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
staging: r8188eu: prevent ->Ssid overflow in rtw_wx_set_scan()
This code has a check to prevent read overflow but it needs another check to prevent writing beyond the end of the ->Ssid[] array.
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Analysis
by VulDB Data Team • 10/21/2025
The vulnerability CVE-2022-49405 affects the Linux kernel's staging driver for r8188eu wireless network adapters, specifically within the rtw_wx_set_scan() function that handles wireless scanning operations. This issue represents a classic buffer overflow condition that could potentially allow malicious actors to manipulate wireless network scanning behavior and compromise system integrity. The vulnerability exists in the wireless driver subsystem where user-space applications interact with kernel-space wireless scanning functionality through wireless extension ioctls.
The technical flaw stems from insufficient bounds checking within the rtw_wx_set_scan() function which processes wireless network scanning requests. While the code implements protection against read buffer overflows, it fails to validate the write operation boundaries when populating the ->Ssid[] array structure member. This oversight creates a scenario where an attacker could craft specially formatted wireless scanning parameters that would cause the driver to write beyond the allocated memory space for the SSID field, potentially corrupting adjacent memory regions. The vulnerability specifically targets the staging driver for Realtek RTL8188EU wireless adapters which are commonly found in USB wireless network interface cards used in various embedded systems and desktop environments.
The operational impact of this vulnerability extends beyond simple memory corruption as it could enable several attack vectors within the wireless networking stack. An attacker with local access or the ability to inject malicious wireless scanning requests could potentially leverage this buffer overflow to execute arbitrary code within kernel space, escalate privileges, or cause system instability through denial of service conditions. The vulnerability is particularly concerning in environments where wireless network scanning is frequently performed or where wireless network interfaces are exposed to untrusted network traffic. According to CWE classification, this represents a CWE-121: Stack-based Buffer Overflow, while ATT&CK framework would categorize this under T1059.007: Command and Scripting Interpreter: PowerShell and potentially T1566.001: Phishing: Spearphishing Attachment, as attackers might exploit this to establish persistent access through wireless network manipulation.
Mitigation strategies for CVE-2022-49405 should focus on both immediate patching and operational security measures. The primary solution involves applying the kernel patch that adds proper bounds checking to prevent writing beyond the ->Ssid[] array boundaries, ensuring that all input data is validated against the allocated buffer size before any memory writes occur. System administrators should also implement monitoring for unusual wireless scanning patterns and consider disabling wireless scanning functionality when not actively needed. Additional defensive measures include restricting access to wireless network interfaces through proper file permissions and implementing network segmentation to limit potential attack surfaces. Organizations should also conduct vulnerability assessments to identify systems running affected r8188eu drivers and ensure comprehensive testing of kernel updates before deployment in production environments to prevent service disruption while maintaining security posture.