CVE-2022-24142 in AX3
Summary
by MITRE • 02/04/2022
Tenda AX3 v16.03.12.10_CN was discovered to contain a stack overflow in the function formSetFirewallCfg. This vulnerability allows attackers to cause a Denial of Service (DoS) via the firewallEn parameter.
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Analysis
by VulDB Data Team • 02/05/2022
The vulnerability identified as CVE-2022-24142 affects the Tenda AX3 wireless router firmware version v16.03.12.10_CN, presenting a critical stack overflow condition within the formSetFirewallCfg function. This flaw represents a classic buffer overflow vulnerability that occurs when an attacker provides excessive input data to the firewallEn parameter, which is processed without adequate bounds checking. The stack overflow vulnerability falls under CWE-121, which specifically addresses stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations on the program stack. The affected device operates under a web-based administration interface where the firewallEn parameter is typically submitted through HTTP POST requests to the router's configuration management functions.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious payload containing excessive data in the firewallEn parameter, causing the function to write beyond the allocated stack buffer space. This overflow corrupts the return address and other critical stack variables, leading to unpredictable program behavior and ultimately resulting in a denial of service condition. The attacker does not require elevated privileges or authentication to trigger this vulnerability, making it particularly dangerous as it can be exploited remotely through the web administration interface. The vulnerability demonstrates a failure in input validation and memory management practices, where the firmware fails to implement proper bounds checking before copying user-supplied data into fixed-size buffers.
The operational impact of this vulnerability extends beyond simple service disruption, as it can render the entire router administration interface inaccessible and potentially cause the device to crash entirely. Network administrators may experience complete loss of remote management capabilities, forcing them to perform manual recovery procedures including physical access to the device for firmware reinstallation. The denial of service condition affects all network services that depend on the router's firewall functionality, potentially exposing the network to unauthorized access while the device remains non-functional. This vulnerability particularly impacts enterprise environments where remote management of network infrastructure is critical, as it can lead to extended downtime and increased operational costs due to the need for on-site intervention.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from Tenda, as the vendor has likely released patches addressing the stack overflow condition. Network administrators should implement network segmentation and access control measures to limit exposure of vulnerable devices to untrusted networks, while also considering disabling unnecessary web administration interfaces when not actively required. The implementation of network monitoring tools capable of detecting anomalous traffic patterns associated with exploitation attempts can provide early warning of potential attacks. Security teams should also consider implementing intrusion detection systems that can identify and block malicious requests containing oversized firewallEn parameters. Organizations should follow ATT&CK framework techniques related to defensive measures such as T1562.001 (Impairing Defenses) and T1071.004 (Application Layer Protocol: DNS) to monitor for exploitation attempts and maintain network integrity. Additionally, regular vulnerability assessments and penetration testing should be conducted to identify similar buffer overflow conditions in other network infrastructure components, as this represents a common class of vulnerability in embedded systems and network devices that require robust input validation mechanisms to prevent exploitation.