CVE-2017-12273 in Aironet
Summary
by MITRE
A vulnerability in 802.11 association request frame processing for the Cisco Aironet 1560, 2800, and 3800 Series Access Points could allow an unauthenticated, Layer 2 radio frequency (RF) adjacent attacker to cause the Access Point (AP) to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient frame validation of the 802.11 association request. An attacker could exploit this vulnerability by sending a malformed 802.11 association request to the targeted device. An exploit could allow the attacker to cause the AP to reload, resulting in a DoS condition while the AP is reloading. This vulnerability affects the following Cisco products running either the Lightweight AP Software or Mobility Express image: Aironet 1560 Series Access Points, Aironet 2800 Series Access Points, Aironet 3800 Series Access Points. Note: The Cisco Aironet 1560 Series Access Point device is supported as of release 8.3.112.0. Cisco Bug IDs: CSCve12189.
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Analysis
by VulDB Data Team • 01/21/2021
The vulnerability identified as CVE-2017-12273 represents a critical denial of service weakness in Cisco's enterprise wireless infrastructure, specifically affecting Aironet 1560, 2800, and 3800 Series Access Points. This flaw resides in the 802.11 association request frame processing mechanism, which serves as a fundamental component in wireless network authentication and connection establishment. The vulnerability demonstrates a classic example of insufficient input validation where the access point fails to properly validate incoming association requests, creating an exploitable condition that can be leveraged by malicious actors within the radio frequency coverage area. The security implications extend beyond simple service disruption as this weakness directly impacts the operational continuity of wireless networks that depend on these access points for connectivity.
The technical exploitation of this vulnerability occurs through the manipulation of 802.11 association request frames, which are standard wireless communication messages used to establish connections between wireless devices and access points. Attackers can craft malformed association requests that bypass normal validation procedures, causing the targeted access point to crash and subsequently reload its operating system. This process creates a temporary network outage that affects all wireless clients connected to the vulnerable access point, effectively rendering the wireless service unavailable during the reload process. The flaw specifically targets the Lightweight AP Software and Mobility Express image versions, indicating that the vulnerability exists in the core wireless protocol handling code rather than in application-layer components. This type of vulnerability aligns with CWE-20, which describes "Improper Input Validation" as a common weakness that can lead to various security issues including denial of service conditions.
The operational impact of CVE-2017-12273 extends significantly beyond the immediate technical disruption it causes, as wireless access points serve as critical infrastructure components in enterprise environments, educational institutions, and public wireless networks. When an access point reloads due to this vulnerability, all connected wireless devices lose network connectivity, potentially affecting business operations, emergency services, or public access to communication networks. The vulnerability's location within the Layer 2 wireless frame processing means that attackers need only be within RF coverage area of the targeted device, making exploitation relatively straightforward compared to network-layer attacks. This proximity requirement aligns with ATT&CK technique T1046, which involves network service scanning and reconnaissance, as attackers can potentially identify vulnerable access points through wireless network discovery activities. The DoS condition created by this vulnerability can persist for several minutes while the access point reinitializes its services, providing attackers with sufficient time to conduct multiple attacks or escalate their activities.
Cisco's response to this vulnerability included the release of software updates addressing the insufficient frame validation issue in the affected access point models. The fix required implementing proper validation checks on 802.11 association request frames to ensure they conform to expected parameters before processing. Network administrators should prioritize patching affected devices, particularly in environments where wireless connectivity is critical for operations. The vulnerability highlights the importance of robust input validation in wireless network protocols and demonstrates how seemingly minor protocol handling flaws can create significant security risks. Organizations should implement monitoring solutions to detect unusual access point behavior or frequent reloads that might indicate exploitation attempts. Additionally, network segmentation strategies can help limit the impact of such attacks by preventing lateral movement within the wireless infrastructure. The vulnerability also underscores the necessity of maintaining current security patches for wireless network equipment, as many organizations may not regularly update their wireless access point firmware, leaving them exposed to known vulnerabilities like CVE-2017-12273.