CVE-2022-43028 is a critical stack overflow vulnerability identified in the Tenda TX3 router firmware version US_TX3V1.0br_V16.03.13.11_multi_TDE01. The vulnerability arises from improper handling of the timeZone parameter in the /goform/SetSysTimeCfg endpoint. Specifically, the stack overflow (CWE-787) occurs when the timeZone parameter is processed without adequate bounds checking, allowing an attacker to overwrite the stack memory. This flaw can be exploited remotely over the network without any authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). Successful exploitation can lead to arbitrary code execution with the privileges of the affected process, resulting in full compromise of the device’s confidentiality, integrity, and availability. The vulnerability has a CVSS v3.1 base score of 9.8, reflecting its critical severity. Although no public exploit code or active exploitation in the wild has been reported to date, the ease of exploitation and the critical impact make this a significant threat. The affected product is a consumer-grade router, which is commonly used in home and small office environments, potentially exposing a broad attack surface if devices are internet-facing or accessible within local networks.

For European organizations, this vulnerability poses a substantial risk, especially for small and medium enterprises (SMEs) and home office setups that rely on Tenda TX3 routers for internet connectivity. Exploitation could allow attackers to gain persistent control over network gateways, enabling interception or manipulation of network traffic, deployment of malware, lateral movement within internal networks, and disruption of business operations. The compromise of router devices can also facilitate further attacks on connected systems and exfiltration of sensitive data. Given the critical nature of the vulnerability and the lack of authentication required, attackers could remotely exploit vulnerable devices exposed to the internet or accessible through compromised internal networks. This risk is heightened in sectors with sensitive data or critical infrastructure, such as finance, healthcare, and government agencies, where network integrity and confidentiality are paramount. Additionally, the potential for widespread impact exists if large numbers of Tenda TX3 routers are deployed within European homes and offices without timely patching or mitigation.

To mitigate this vulnerability effectively, European organizations and users should: 1) Immediately check if their network infrastructure includes Tenda TX3 routers running the affected firmware version US_TX3V1.0br_V16.03.13.11_multi_TDE01. 2) Since no official patch or update link is currently available, contact Tenda support or monitor official channels for firmware updates addressing this vulnerability. 3) As an interim measure, restrict remote access to the router’s management interface by disabling WAN-side administration and limiting access to trusted internal IP addresses only. 4) Implement network segmentation to isolate vulnerable routers from critical systems and sensitive data environments. 5) Employ network intrusion detection/prevention systems (IDS/IPS) to monitor and block suspicious traffic targeting the /goform/SetSysTimeCfg endpoint or unusual HTTP POST requests containing oversized or malformed timeZone parameters. 6) Encourage users to change default credentials and enforce strong authentication policies to reduce the risk of secondary attacks. 7) Regularly audit network devices for firmware versions and vulnerabilities to maintain an up-to-date security posture. 8) Consider replacing vulnerable devices with models from vendors that provide timely security updates if patches are not forthcoming.