CVE-2023-25218 in AC5
Summary
by MITRE • 04/07/2023
Tenda AC5 US_AC5V1.0RTL_V15.03.06.28 was discovered to contain a stack overflow via the form_fast_setting_wifi_set function. This vulnerability allows attackers to cause a Denial of Service (DoS) or execute arbitrary code via a crafted payload.
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Analysis
by VulDB Data Team • 10/29/2025
The vulnerability identified as CVE-2023-25218 represents a critical stack overflow condition within the Tenda AC5 US_AC5V1.0RTL_V15.03.06.28 firmware implementation. This flaw manifests specifically within the form_fast_setting_wifi_set function, which processes wireless configuration parameters submitted through the device's web interface. The stack overflow occurs when the firmware fails to properly validate input lengths before copying data to stack-based buffers, creating an exploitable condition that can be leveraged by remote attackers to gain unauthorized system control. The vulnerability resides in the device's web server component responsible for handling administrative configuration requests, making it accessible through standard network protocols without requiring physical access or authentication.
The technical exploitation of this vulnerability follows established patterns for stack-based buffer overflow attacks as categorized under CWE-121. When an attacker submits a maliciously crafted payload containing excessive data to the vulnerable form_fast_setting_wifi_set function, the firmware's insufficient input validation causes the data to overflow into adjacent stack memory locations. This overflow can overwrite return addresses, function pointers, and other critical execution context data, potentially allowing attackers to redirect program execution flow. The attack vector is particularly concerning as it operates over the network without requiring authentication, enabling remote exploitation from any location with network access to the device's web interface.
The operational impact of this vulnerability extends beyond simple denial of service conditions to encompass full system compromise capabilities. An attacker who successfully exploits this vulnerability can execute arbitrary code with the highest privileges available to the web server process, potentially gaining root access to the embedded device. This level of compromise allows for complete system control including but not limited to modifying network configurations, installing persistent backdoors, accessing stored credentials, and using the device as a pivot point for further attacks within the local network. The device's role as a wireless access point makes it particularly valuable as an attack vector for lateral movement and network reconnaissance activities, aligning with tactics described in the attack pattern taxonomy under ATT&CK framework category TA0001 (Initial Access) and TA0003 (Persistence).
Mitigation strategies for CVE-2023-25218 should prioritize immediate firmware updates from Tenda's official support channels, as the vendor has likely released patches addressing this specific vulnerability. Network administrators should implement network segmentation to limit access to affected devices and monitor for suspicious network activity originating from these devices. Additional protective measures include disabling unnecessary web interfaces, implementing strict firewall rules restricting access to device management ports, and conducting regular security audits of networked embedded devices. The vulnerability's nature suggests that any device running the affected firmware version requires immediate attention, as the stack overflow condition provides a direct path to system compromise without requiring specialized attack skills beyond basic network reconnaissance. Security teams should also consider implementing intrusion detection systems capable of identifying malformed requests targeting the vulnerable form_fast_setting_wifi_set endpoint, as this would provide early warning of exploitation attempts.