CVE-2025-53713 is a medium-severity buffer overflow vulnerability identified in the TP-Link TL-WR841N V11 wireless router. The flaw resides in the handling of the /userRpm/WlanNetworkRpm_APC.htm web interface file, where insufficient input validation allows an attacker to overflow a buffer. This classic buffer overflow (CWE-120) can be triggered remotely without user interaction or authentication, causing the embedded web service to crash and resulting in a denial-of-service (DoS) condition. The vulnerability stems from the failure to properly check the size of input parameters before copying them into fixed-size buffers, a common programming error that can lead to memory corruption. Although the CVSS 4.0 base score is 6.9 (medium), the impact is primarily limited to service disruption rather than remote code execution. The affected product, TL-WR841N V11, is no longer supported by TP-Link, and no patches are available, increasing the risk for users who continue to operate this hardware. No known exploits have been reported in the wild as of the publication date. The vulnerability requires no authentication and can be exploited over the network, making it accessible to remote attackers. However, the scope is limited to this specific router model and firmware version. This vulnerability highlights the risks of using unsupported network devices in operational environments, as they may harbor unpatched security flaws that can be leveraged to disrupt network availability.

For European organizations, the primary impact of this vulnerability is the potential for denial-of-service attacks against network infrastructure relying on the TP-Link TL-WR841N V11 router. Disruption of wireless network services could affect business continuity, especially for small and medium enterprises or branch offices that use this cost-effective router model. Although the vulnerability does not enable remote code execution or data compromise, the loss of network availability can hinder operations, cause productivity losses, and increase support costs. Additionally, since the device is no longer supported, organizations cannot rely on vendor patches, forcing them to consider device replacement or network segmentation to mitigate risks. In sectors with strict uptime requirements or regulatory compliance (e.g., finance, healthcare), such DoS vulnerabilities could have compliance and reputational consequences. The ease of remote exploitation without authentication increases the threat level, particularly in environments where these routers are exposed to untrusted networks or the internet. However, the impact is mitigated if the vulnerable devices are not internet-facing or are protected by network perimeter controls.

Given the lack of vendor support and absence of patches, European organizations should prioritize the following specific mitigation strategies: 1) Immediate inventory and identification of all TP-Link TL-WR841N V11 devices in the network to assess exposure. 2) Segregate or isolate vulnerable devices from untrusted networks, especially the internet, using firewalls or VLAN segmentation to limit remote access to the router's web interface. 3) Disable remote management features on these routers to reduce the attack surface. 4) Replace unsupported TL-WR841N V11 devices with newer, supported hardware that receives regular security updates. 5) Implement network monitoring to detect unusual traffic patterns or repeated access attempts to the vulnerable web interface endpoint (/userRpm/WlanNetworkRpm_APC.htm). 6) Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics to identify exploitation attempts targeting this vulnerability. 7) Educate network administrators about the risks of using unsupported devices and enforce policies to avoid deploying end-of-life hardware in critical network segments. These targeted actions go beyond generic advice by focusing on device-specific controls and network architecture adjustments to mitigate the risk in the absence of patches.