CVE-2026-21094 in Samsung
Summary
by MITRE • 09/09/2026
Improper input validation in wpa_supplicant prior to SMR Sep-2026 Release 1 allows adjacent attackers to write out-of-bounds memory.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified involves a critical failure in the input validation mechanisms within wpa_supplicant, specifically affecting versions released before the September 2026 Release 1 update. As a foundational component for managing Wi-Fi Protected Access (WPA) connections on Linux and other Unix-like operating systems, wpa_supplicant is responsible for handling complex authentication protocols including WEP, WPA/WPA2, and IEEE 802.1X/EAP. The flaw resides in the processing of specific management frames or configuration inputs where boundary checks are either absent or incorrectly implemented. This deficiency allows an attacker positioned within wireless range to craft maliciously formatted packets that exploit the lack of rigorous validation, leading directly to out-of-bounds memory writes.
From a technical perspective, this issue classifies under CWE-787: Out-of-Bounds Write, which is widely recognized as one of the most dangerous classes of software vulnerabilities due to its potential for arbitrary code execution. When wpa_supplicant processes data from adjacent wireless devices without verifying that the input length or structure fits within allocated memory buffers, it overwrites contiguous memory locations. This corruption can overwrite critical control structures such as return addresses, function pointers, or exception handlers stored on the stack or heap. The proximity requirement implies that this is a local network attack vector, requiring physical or logical adjacency to the target device's wireless interface, which aligns with ATT&CK technique T1046: Network Service Discovery followed by exploitation via adjacent access points or rogue devices.
The operational impact of this vulnerability extends beyond simple denial of service, although that remains a likely outcome if memory corruption causes a crash in the supplicant process. More critically, successful exploitation could allow an attacker to execute arbitrary code with the privileges of the wpa_supplicant process. Depending on system configuration and user permissions, this may grant elevated access rights or enable lateral movement within the network infrastructure. Since wpa_supplicant often runs with significant privileges to manage network interfaces and keys, compromising it can lead to full system compromise, interception of encrypted traffic through key extraction, or manipulation of network routing tables. The lack of proper input validation means that even seemingly benign configuration updates or association requests from nearby devices can trigger this memory corruption if they contain specifically crafted payloads designed to exceed expected buffer limits.
Mitigation strategies must prioritize immediate patching by upgrading wpa_supplicant to Release 1 dated September 2026 or later, where the input validation logic has been corrected to enforce strict boundary checks on all incoming data streams. In environments where updating is not immediately feasible, network segmentation and wireless intrusion detection systems can help identify anomalous packet structures associated with this exploit attempt. Additionally, restricting wpa_supplicant execution privileges through sandboxing techniques such as SELinux or AppArmor profiles can limit the impact of a successful exploitation by confining the process to minimal necessary permissions. Regular auditing of configuration files and disabling unnecessary WPA features on devices that do not require them further reduces the attack surface available to adjacent attackers seeking to leverage this memory corruption flaw.