CVE-2025-55564 is a stack overflow vulnerability identified in the Tenda AC15 router firmware version v15.03.05.19_multi_TD01. The vulnerability arises from improper handling of the 'list' parameter in the fromSetIpMacBind function. A stack overflow occurs when the function processes this parameter without adequate bounds checking, allowing an attacker to overwrite the stack memory. This can lead to arbitrary code execution, denial of service, or system instability. The vulnerability is particularly critical because routers like the Tenda AC15 are often deployed in home and small office environments, acting as gateways to internal networks. Exploiting this vulnerability could allow an attacker to gain control over the device, intercept or manipulate network traffic, or pivot to other devices within the network. The lack of a CVSS score and absence of known exploits in the wild suggest that this vulnerability is newly disclosed and may not yet be actively exploited. However, the technical nature of a stack overflow in a network device firmware indicates a high-risk potential if weaponized. The fromSetIpMacBind function likely relates to binding IP addresses to MAC addresses, a common feature in routers for network management and security, which means the vulnerability could be triggered remotely if the affected function is accessible via network interfaces. No patches or mitigations have been published at the time of disclosure, increasing the urgency for affected users to monitor for updates or apply interim protective measures.

For European organizations, the impact of this vulnerability can be significant, especially for small and medium enterprises (SMEs) and home office setups relying on Tenda AC15 routers. Compromise of these routers could lead to unauthorized access to internal networks, interception of sensitive communications, and potential lateral movement to critical infrastructure or corporate resources. Given the router's role as a network gateway, exploitation could undermine confidentiality, integrity, and availability of organizational data and services. Additionally, compromised routers could be leveraged as part of botnets or for launching further attacks, increasing the threat landscape. The absence of known exploits currently limits immediate risk, but the potential for rapid weaponization exists. European organizations with remote or hybrid workforces using such consumer-grade equipment are particularly vulnerable, as attackers might exploit this vulnerability to bypass perimeter defenses. The impact extends beyond individual organizations to critical infrastructure sectors if these devices are used in operational environments without adequate segmentation or monitoring.

Since no official patches are currently available, European organizations should implement the following specific mitigations: 1) Identify and inventory all Tenda AC15 routers within their networks to assess exposure. 2) Restrict access to router management interfaces by limiting them to trusted internal IP addresses and disabling remote management where possible. 3) Employ network segmentation to isolate vulnerable devices from critical systems and sensitive data. 4) Monitor network traffic for unusual activity that could indicate exploitation attempts, such as unexpected connections or anomalous IP-MAC binding requests. 5) Use intrusion detection/prevention systems (IDS/IPS) with updated signatures to detect potential stack overflow exploitation patterns. 6) Encourage users to replace vulnerable routers with updated or alternative devices if firmware updates are not forthcoming. 7) Maintain vigilance for vendor announcements regarding patches or firmware updates and apply them promptly once available. 8) Implement strong network access controls and multi-factor authentication on management interfaces to reduce the risk of unauthorized exploitation.