CVE-2017-12283 in Aironet
Summary
by MITRE
A vulnerability in the handling of 802.11w Protected Management Frames (PAF) by Cisco Aironet 3800 Series Access Points could allow an unauthenticated, adjacent attacker to terminate a valid user connection to an affected device, aka Denial of Service. The vulnerability exists because the affected device does not properly validate 802.11w PAF disassociation and deauthentication frames that it receives. An attacker could exploit this vulnerability by sending a spoofed 802.11w PAF frame from a valid, authenticated client on an adjacent network to an affected device. A successful exploit could allow the attacker to terminate a single valid user connection to the affected device. This vulnerability affects Access Points that are configured to run in FlexConnect mode. Cisco Bug IDs: CSCvc20627.
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Analysis
by VulDB Data Team • 01/21/2021
The vulnerability described in CVE-2017-12283 represents a significant security flaw in Cisco Aironet 3800 Series Access Points that specifically impacts the handling of 802.11w Protected Management Frames. This vulnerability operates within the context of wireless network security protocols where 802.11w was designed to provide protection against malicious management frame attacks by requiring cryptographic protection for certain management frames including disassociation and deauthentication frames. The flaw manifests in the access point's failure to properly validate the authenticity of these protected management frames, creating a pathway for unauthorized disruption of legitimate wireless connections. The vulnerability is particularly concerning because it requires only adjacent network access and does not necessitate authentication, making it exploitable by attackers who can physically proximity to the affected network infrastructure.
The technical implementation of this vulnerability stems from the improper validation mechanisms within the Cisco Aironet 3800 Series Access Points when processing 802.11w Protected Management Frames. According to the Cisco Bug ID CSCvc20627, the affected devices do not adequately verify the cryptographic integrity of disassociation and deauthentication frames that are supposed to be protected under the 802.11w standard. This validation failure occurs specifically when the access point receives spoofed frames from what appears to be a legitimate authenticated client on the adjacent network. The flaw essentially allows an attacker to masquerade as a valid client and send malicious frames that the access point accepts as legitimate, causing it to terminate valid user connections without proper authentication verification. This represents a critical breakdown in the cryptographic protection mechanisms that 802.11w was designed to provide.
The operational impact of this vulnerability extends beyond simple service disruption to represent a targeted attack vector that can specifically compromise user connectivity within wireless networks. An attacker exploiting this vulnerability can selectively terminate individual user connections to the affected access point, effectively creating a denial of service condition that impacts specific network users rather than entire network segments. The vulnerability is particularly dangerous in enterprise environments where wireless connectivity is critical for business operations, as it allows attackers to disrupt specific user sessions without requiring complex network penetration techniques. This targeted approach makes the vulnerability more dangerous than broad network disruption attacks and aligns with the attacker methodology described in the ATT&CK framework under network denial of service tactics. The fact that the vulnerability affects devices operating in FlexConnect mode adds another layer of complexity since these devices often serve as critical network bridges between wired and wireless infrastructures.
Mitigation strategies for this vulnerability should focus on both immediate network protection measures and long-term architectural improvements. Cisco recommends applying the appropriate software patches and firmware updates to address the validation flaw in the 802.11w frame handling mechanisms. Network administrators should also consider implementing additional network segmentation measures to limit the adjacency attack surface, ensuring that wireless networks are properly isolated from unauthorized physical access points. The vulnerability's classification under CWE-284 (Improper Access Control) highlights the need for proper validation of management frame authenticity, while its alignment with ATT&CK techniques for wireless network attacks emphasizes the importance of implementing robust wireless security monitoring. Organizations should also consider deploying intrusion detection systems specifically designed to monitor for suspicious 802.11 management frame activity and implement proper network access control measures to prevent unauthorized physical access to wireless infrastructure. The vulnerability demonstrates the critical importance of proper cryptographic frame validation in wireless security protocols and serves as a reminder of the ongoing challenges in securing wireless network infrastructure against sophisticated attack vectors.