CVE-2025-13258 identifies a buffer overflow vulnerability in the Tenda AC20 wireless router firmware versions up to 16.03.08.12. The vulnerability resides in an unspecified function handling requests to the /goform/WifiExtraSet endpoint, specifically through the manipulation of the wpapsk_crypto parameter. This parameter is improperly validated, allowing an attacker to overflow a buffer remotely without authentication or user interaction. The buffer overflow can lead to memory corruption, enabling an attacker to execute arbitrary code with elevated privileges or cause a denial of service by crashing the device. The vulnerability has a CVSS 4.0 base score of 8.7, indicating high severity, with attack vector network (remote), low attack complexity, no privileges required, and no user interaction needed. The impact covers confidentiality, integrity, and availability, with high exploitability and scope limited to the device itself. Although no exploits have been observed in the wild, a public exploit is available, increasing the urgency for mitigation. The vulnerability affects multiple firmware versions from 16.03.08.0 through 16.03.08.12, all of which should be considered vulnerable until patched. The lack of official patch links suggests that users must monitor vendor advisories closely or apply workarounds to mitigate risk.

For European organizations, this vulnerability poses a significant risk, particularly for enterprises and service providers using Tenda AC20 routers in their network infrastructure. Successful exploitation could allow attackers to gain remote control over affected routers, leading to interception or manipulation of network traffic, disruption of internet connectivity, or pivoting to internal networks for further compromise. This is especially critical for organizations relying on these devices for secure Wi-Fi access or remote management. The confidentiality of sensitive data could be compromised, integrity of network configurations altered, and availability of network services disrupted. Given the public availability of an exploit and the remote, unauthenticated attack vector, the threat landscape is elevated. Organizations with exposed management interfaces or weak network segmentation are at higher risk. The impact extends to critical infrastructure sectors, SMBs, and home office environments that use Tenda AC20 devices, potentially affecting business continuity and data protection compliance under GDPR.

1. Immediately identify and inventory all Tenda AC20 devices within the network and verify their firmware versions. 2. Apply vendor-provided firmware updates as soon as they become available; monitor Tenda’s official channels for patches addressing CVE-2025-13258. 3. If patches are not yet available, restrict access to the /goform/WifiExtraSet endpoint by implementing network-level controls such as firewall rules or access control lists limiting management interface exposure. 4. Disable remote management features on Tenda AC20 devices unless absolutely necessary, and if enabled, restrict access to trusted IP addresses only. 5. Employ network segmentation to isolate vulnerable devices from critical network segments. 6. Monitor network traffic for unusual activity targeting the vulnerable endpoint or unusual buffer overflow exploit signatures. 7. Consider replacing Tenda AC20 devices with alternative hardware if timely patching is not feasible. 8. Educate IT staff about the vulnerability and ensure incident response plans include steps for potential exploitation scenarios.