CVE-2023-40894 in AC8
Summary
by MITRE • 08/24/2023
Tenda AC8 v4 US_AC8V4.0si_V16.03.34.06_cn was discovered to contain a stack overflow via parameter list at /goform/SetStaticRouteCfg.
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Analysis
by VulDB Data Team • 01/30/2026
The vulnerability identified as CVE-2023-40894 represents a critical stack overflow flaw within the Tenda AC8 v4 US_AC8V4.0si_V16.03.34.06_cn firmware implementation. This vulnerability manifests specifically within the /goform/SetStaticRouteCfg endpoint, which serves as a web form handler for configuring static routing parameters on the device. The flaw arises from insufficient input validation and sanitization of user-supplied parameters passed to this function, creating an exploitable condition that allows remote attackers to manipulate the device's memory structure through crafted input sequences.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking permits data to overwrite adjacent memory locations on the program stack. When an attacker submits maliciously crafted parameters to the SetStaticRouteCfg endpoint, the device's web server processes these inputs without adequate verification, leading to a situation where the stack can be overwritten with attacker-controlled data. This condition enables arbitrary code execution or system crashes, depending on the specific payload and exploitation methodology employed.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it provides potential attackers with remote code execution capabilities on the affected router. Given that the Tenda AC8 is a consumer-grade wireless router commonly deployed in home and small office environments, the exploitation of this vulnerability could allow attackers to gain full administrative control over the device. This control would enable various malicious activities including but not limited to network traffic interception, DNS hijacking, port forwarding modifications, and potential lateral movement within the compromised network. The vulnerability affects the device's web management interface, making exploitation relatively straightforward for attackers who can access the router's network.
Security professionals should consider this vulnerability in the context of ATT&CK framework technique T1059.007, which covers command and scripting interpreter usage through web shells or remote access capabilities. The impact of such a vulnerability also relates to the broader category of IoT security concerns where firmware-level vulnerabilities can provide attackers with persistent access to network infrastructure. Organizations should implement immediate mitigations including firmware updates from Tenda, network segmentation to limit access to affected devices, and monitoring for suspicious network traffic patterns that might indicate exploitation attempts. Additionally, the vulnerability highlights the importance of input validation practices and proper memory management in embedded systems, as outlined in industry best practices for secure software development lifecycle processes.
The exploitation of this vulnerability demonstrates the ongoing challenges in securing consumer networking equipment where security updates are often infrequently deployed and users may not be aware of the risks associated with unpatched firmware. Network administrators should prioritize inventory management to identify all affected Tenda AC8 devices within their networks and ensure prompt remediation through official firmware updates provided by the manufacturer. The vulnerability serves as a reminder of the critical need for robust security testing of embedded systems and the importance of maintaining up-to-date security patches for network infrastructure devices.