CVE-2025-13445 in AC21
Summary
by MITRE • 11/20/2025
A flaw has been found in Tenda AC21 16.03.08.16. This affects an unknown part of the file /goform/SetIpMacBind. Executing manipulation of the argument list can lead to stack-based buffer overflow. The attack can be executed remotely. The exploit has been published and may be used.
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Analysis
by VulDB Data Team • 11/21/2025
The vulnerability identified as CVE-2025-13445 affects the Tenda AC21 router firmware version 16.03.08.16 and resides within the /goform/SetIpMacBind file component. This represents a critical security flaw that undermines the device's input validation mechanisms, specifically targeting the handling of argument lists in the web-based administrative interface. The issue manifests as a stack-based buffer overflow condition that occurs when processing user-supplied parameters through the affected API endpoint, creating a potential entry point for malicious actors to compromise the device's operational integrity.
The technical exploitation of this vulnerability leverages improper bounds checking within the router's firmware implementation, where the application fails to adequately validate the length and content of input parameters passed to the SetIpMacBind function. This deficiency allows attackers to craft specially formatted payloads that exceed the allocated buffer space on the stack, potentially leading to arbitrary code execution or system crash conditions. The vulnerability's remote exploitability means that attackers do not require physical access to the device, as the flaw exists within the web interface that is accessible over the network. The published exploit demonstrates the practical nature of this threat, indicating that threat actors have already developed working methods to leverage this weakness.
From an operational perspective, this vulnerability poses significant risks to network security infrastructure, particularly when considering that routers serve as fundamental gateways for network traffic and often operate with elevated privileges. The stack-based buffer overflow could enable attackers to execute malicious code with the privileges of the web server process, potentially leading to complete device compromise, unauthorized network access, or use as a pivot point for further attacks within the network. The impact extends beyond individual device compromise, as compromised routers can provide attackers with persistent access to entire network segments and enable advanced persistent threat campaigns.
Security practitioners should immediately implement mitigations including firmware updates from Tenda, network segmentation to limit exposure, and monitoring for suspicious traffic patterns targeting the affected API endpoint. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which is categorized under the broader ATT&CK technique of Command and Control through the use of compromised network infrastructure. Organizations should also consider implementing web application firewalls to detect and block malicious requests to the vulnerable endpoint, while conducting thorough network assessments to identify any potential exploitation attempts. The published exploit availability increases the urgency for remediation, as it reduces the attack surface window for potential compromise.