CVE-2021-41753 in DIR-X1560
Summary
by MITRE • 09/28/2021
A denial-of-service attack in WPA2, and WPA3-SAE authentication methods in D-Link DIR-X1560, v1.04B04, and DIR-X6060, v1.11B04 allows a remote unauthenticated attacker to disconnect a wireless client via sending specific spoofed SAE authentication frames.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 10/03/2021
The vulnerability identified as CVE-2021-41753 represents a critical denial-of-service weakness affecting wireless authentication protocols in D-Link DIR-X1560 and DIR-X6060 routers. This security flaw specifically targets the WPA2 and WPA3-SAE authentication mechanisms, which are fundamental components of modern wireless network security infrastructure. The vulnerability stems from inadequate validation of SAE authentication frames, allowing malicious actors to exploit the authentication process through crafted spoofed frames that disrupt legitimate wireless connections.
The technical implementation of this vulnerability resides in the improper handling of SAE (Simultaneous Authentication of Equals) frames within the router's wireless authentication subsystem. When a remote unauthenticated attacker sends specifically crafted spoofed SAE frames, the affected D-Link devices fail to properly validate these frames, leading to authentication session disruption. This flaw operates at the wireless protocol level, specifically targeting the handshake process between wireless clients and access points, making it particularly dangerous as it can be exploited without requiring any prior authentication credentials or network access.
The operational impact of this vulnerability extends beyond simple service interruption, as it enables attackers to maintain persistent disruption of wireless connectivity for legitimate users. The attack vector requires only network access to send spoofed frames, making it highly accessible to remote threat actors. This capability allows for targeted disruption of wireless services, potentially affecting business operations, user productivity, and overall network availability. The vulnerability affects both WPA2 and WPA3-SAE protocols, indicating a fundamental flaw in the wireless authentication implementation that impacts multiple security standards and protocols.
From a cybersecurity perspective, this vulnerability aligns with CWE-20, which describes improper input validation, and represents a significant weakness in the authentication framework that could enable broader attack vectors. The ATT&CK framework categorizes this as a denial-of-service attack technique, specifically targeting network services and potentially enabling further exploitation through service disruption. Organizations using affected D-Link devices face increased risk of network availability attacks, with potential for extended service disruption that could impact critical business operations. The vulnerability demonstrates the importance of proper frame validation in wireless authentication protocols and highlights the need for robust input sanitization in network security implementations.
Mitigation strategies should prioritize immediate firmware updates from D-Link to address the authentication frame validation weakness. Network administrators should implement additional monitoring of wireless authentication frames to detect anomalous activity patterns that may indicate exploitation attempts. The implementation of wireless intrusion detection systems can help identify and alert on suspicious SAE frame behavior, while network segmentation strategies can limit the scope of potential disruption. Organizations should also consider implementing temporary network access controls to reduce the attack surface until permanent patches are deployed. Regular security assessments of wireless infrastructure components are essential to identify similar validation weaknesses in other network equipment that may be subject to comparable exploitation techniques.