CVE-2025-29387 in AC9
Summary
by MITRE • 03/14/2025
In Tenda AC9 v1.0 V15.03.05.14_multi, the wanSpeed parameter of /goform/AdvSetMacMtuWan has a stack overflow vulnerability, which can lead to remote arbitrary code execution.
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Analysis
by VulDB Data Team • 06/04/2025
The vulnerability identified as CVE-2025-29387 affects the Tenda AC9 v1.0 V15.03.05.14_multi firmware, representing a critical stack overflow flaw within the web interface configuration handler. This vulnerability resides in the /goform/AdvSetMacMtuWan endpoint where the wanSpeed parameter is processed without adequate input validation or bounds checking, creating a pathway for malicious actors to exploit the device's memory management. The stack overflow occurs when an attacker supplies a crafted input to the wanSpeed parameter, causing the program to write beyond the allocated stack buffer space and potentially overwrite adjacent memory locations including return addresses and control data. This type of vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is classified as a high-severity issue in the Common Weakness Enumeration catalog and represents a fundamental flaw in memory safety practices.
The operational impact of this vulnerability extends beyond simple denial of service, as it enables remote arbitrary code execution capabilities that could allow attackers to gain full control over the affected device. An attacker can remotely exploit this vulnerability by sending specially crafted HTTP requests to the vulnerable endpoint, potentially leading to complete system compromise including unauthorized access to network resources, data exfiltration, or the installation of persistent backdoors. The attack surface is particularly concerning given that the vulnerability exists in a router firmware that typically operates in network-perimeter environments where it serves as a gateway for multiple devices, making it an attractive target for attackers seeking to establish persistent access points within networks. This vulnerability directly aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1071.001 for Application Layer Protocol, as it enables remote command execution through web-based interfaces.
Mitigation strategies for CVE-2025-29387 should prioritize immediate firmware updates from Tenda to address the stack overflow vulnerability in the affected AC9 router models. Network administrators should implement network segmentation to limit the exposure of affected devices and monitor for suspicious network traffic patterns that might indicate exploitation attempts. Additionally, the deployment of web application firewalls and intrusion detection systems can help detect and prevent exploitation attempts targeting the vulnerable /goform/AdvSetMacMtuWan endpoint. The vulnerability underscores the importance of secure coding practices including input validation, bounds checking, and proper memory management in embedded systems, particularly those handling network configuration interfaces. Organizations should also consider implementing network access controls to restrict access to administrative interfaces and employ regular security assessments of network infrastructure to identify similar vulnerabilities in other network devices that may be running outdated firmware versions.