CVE-2024-20271 in Aironet Access Point
Summary
by MITRE • 03/27/2024
A vulnerability in the IP packet processing of Cisco Access Point (AP) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to insufficient input validation of certain IPv4 packets. An attacker could exploit this vulnerability by sending a crafted IPv4 packet either to or through an affected device. A successful exploit could allow the attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition. To successfully exploit this vulnerability, the attacker does not need to be associated with the affected AP. This vulnerability cannot be exploited by sending IPv6 packets.
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Analysis
by VulDB Data Team • 08/06/2025
This vulnerability resides within the IPv4 packet processing mechanisms of Cisco Access Point software, representing a critical weakness that undermines network availability through unauthorized remote exploitation. The flaw manifests as inadequate input validation specifically targeting certain IPv4 packet structures, creating an entry point for malicious actors to disrupt network operations without requiring authentication or prior association with the targeted device. The vulnerability affects Cisco Access Points running software versions that have not been patched, making it particularly concerning given the widespread deployment of these devices in enterprise and wireless network infrastructures. The security implications extend beyond simple disruption as the DoS condition results in unexpected device reloads that can cascade into broader network service interruptions affecting multiple users and applications dependent on wireless connectivity.
The technical exploitation of this vulnerability leverages the absence of proper validation controls within the IP packet handling pipeline of affected Cisco AP software implementations. When a crafted IPv4 packet is transmitted to or forwarded through an affected device, the insufficient input validation allows malformed or specially constructed packet data to bypass normal processing checks. This failure in input validation creates a condition where the device's packet processing engine encounters unexpected data structures that trigger an internal error state, ultimately leading to an automatic device restart or reload operation. The vulnerability specifically excludes IPv6 packet exploitation, indicating that the flaw is confined to IPv4 processing pathways within the software stack, which suggests the issue may stem from legacy IPv4 handling code that lacks proper boundary checking or data sanitization mechanisms. This limitation in exploit scope does not diminish the severity but rather indicates a targeted weakness within the network stack implementation.
The operational impact of this vulnerability extends beyond simple service disruption to encompass potential business continuity risks and network reliability concerns for organizations relying on Cisco Access Points for wireless infrastructure. When an affected device experiences an unexpected reload, all connected wireless clients lose network connectivity immediately, requiring manual intervention or automatic failover mechanisms to restore service. The vulnerability's remote nature means that attackers can exploit it from anywhere on the network without requiring physical access or network credentials, making it particularly dangerous for organizations with exposed wireless infrastructure. The DoS condition can be sustained through repeated exploitation attempts, potentially leading to prolonged network outages that can affect critical business operations, emergency services, or enterprise applications that depend on uninterrupted wireless connectivity. Network administrators may experience difficulty in identifying the source of disruptions since the attack appears to originate from within the network infrastructure itself.
Mitigation strategies for this vulnerability should prioritize immediate software patching from Cisco, as the vendor has likely released a security advisory containing the necessary updates to address the input validation deficiencies. Organizations should implement network segmentation and access control measures to limit exposure of affected devices to untrusted network segments, reducing the attack surface available to potential exploiters. Monitoring network traffic for unusual packet patterns or repeated connection attempts that might indicate exploitation attempts can provide early detection capabilities. Network administrators should consider implementing intrusion detection systems with signatures specific to known exploit patterns for this vulnerability, as well as establishing automated alerting mechanisms for device restart events that could indicate successful exploitation attempts. The vulnerability aligns with CWE-20, which describes inadequate input validation as a fundamental weakness in software security design, and relates to ATT&CK technique T1499.004 for network denial of service attacks. Organizations should also review their wireless network architecture to ensure proper device management and access controls that prevent unauthorized modifications to network infrastructure components.