CVE-2023-39829 in A18
Summary
by MITRE • 08/15/2023
Tenda A18 V15.13.07.09 was discovered to contain a stack overflow via the wpapsk_crypto2_4g parameter in the fromSetWirelessRepeat function.
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Analysis
by VulDB Data Team • 01/26/2026
The vulnerability identified as CVE-2023-39829 represents a critical stack overflow condition within the Tenda A18 wireless router firmware version V15.13.07.09. This flaw resides in the wireless repeater functionality of the device, specifically within the fromSetWirelessRepeat function that processes wireless security parameters. The vulnerability manifests when the wpapsk_crypto2_4g parameter receives malformed input that exceeds the allocated stack buffer space, creating an exploitable condition that could allow remote code execution or system compromise.
This stack overflow vulnerability falls under the Common Weakness Enumeration category CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The flaw occurs in the wireless repeater configuration handler where user-supplied parameters are processed without adequate input validation or size constraints. The vulnerability is particularly concerning because it affects the wireless security configuration parameters that are typically accessible through web interfaces or API endpoints, making it potentially exploitable from remote network locations.
The operational impact of this vulnerability extends beyond simple denial of service conditions to include potential complete system compromise and unauthorized access to network resources. Attackers could exploit this condition to execute arbitrary code on the affected device, potentially gaining administrative privileges and establishing persistent access to the network infrastructure. The wireless repeater functionality makes this particularly dangerous as it allows attackers to target devices in environments where wireless access points are commonly deployed, such as homes, offices, and public spaces. The vulnerability could enable attackers to perform man-in-the-middle attacks, redirect traffic, or use the compromised device as a pivot point for further network exploration.
Mitigation strategies for this vulnerability should begin with immediate firmware updates from Tenda to address the stack overflow condition through proper input validation and buffer size management. Network administrators should implement network segmentation and access controls to limit exposure of affected devices to untrusted networks. The implementation of intrusion detection systems capable of identifying malformed requests targeting the vulnerable parameter can provide early warning of exploitation attempts. Additionally, security monitoring should include regular vulnerability scanning of network infrastructure to identify other potentially affected devices, as similar stack overflow conditions may exist in other firmware components or related device models. Organizations should also consider disabling unnecessary wireless repeater functionality when not required, reducing the attack surface available to potential exploiters.