CVE-2026-3700 identifies a buffer overflow vulnerability in the UTT HiPER 810G device firmware up to version 1.7.7-171114. The vulnerability arises from improper handling of input data in the strcpy function located in the /goform/formConfigDnsFilterGlobal file. strcpy is a standard C library function that copies strings without bounds checking, making it prone to buffer overflow if input exceeds the allocated buffer size. This flaw allows remote attackers to send specially crafted requests to the affected endpoint, triggering a buffer overflow condition. The vulnerability is remotely exploitable without authentication or user interaction, which significantly increases its risk profile. The CVSS v4.0 base score is 8.7, reflecting high severity due to the ease of exploitation (network vector, low attack complexity), no privileges or user interaction required, and high impact on confidentiality, integrity, and availability. Exploitation could allow attackers to execute arbitrary code, disrupt device operation, or exfiltrate sensitive information. The vulnerability affects a critical network device used in various organizational environments, potentially impacting network security and stability. Although no confirmed active exploitation in the wild has been reported, the availability of a public exploit increases the urgency for remediation. No official patches have been linked yet, so organizations must monitor vendor advisories closely. The vulnerability underscores the risks of unsafe string handling in embedded device firmware and the importance of secure coding practices.

The impact of CVE-2026-3700 is significant for organizations using UTT HiPER 810G devices, as exploitation can lead to remote code execution, complete device compromise, and denial of service. Confidentiality may be breached if attackers access sensitive network configuration or traffic data. Integrity can be undermined by unauthorized changes to device settings or firmware. Availability is at risk due to potential device crashes or reboots caused by buffer overflow exploitation. Given the device’s role in network infrastructure, successful attacks could disrupt enterprise network operations, degrade service quality, or facilitate lateral movement within internal networks. The lack of authentication and user interaction requirements lowers the barrier for attackers, increasing the likelihood of exploitation. The public availability of an exploit further elevates the threat, potentially enabling widespread attacks if unpatched devices remain exposed. Organizations relying on these devices for DNS filtering or other network functions face increased operational and security risks until mitigations or patches are applied.

Organizations should immediately inventory their network to identify any UTT HiPER 810G devices running affected firmware versions. Until an official patch is released, implement network-level protections such as firewall rules to restrict access to the vulnerable /goform/formConfigDnsFilterGlobal endpoint, limiting exposure to trusted management networks only. Employ intrusion detection or prevention systems (IDS/IPS) with signatures targeting this specific exploit to detect and block malicious attempts. Disable or restrict remote management interfaces if not required. Monitor network traffic and device logs for unusual activity indicative of exploitation attempts. Engage with UTT support channels to obtain updates on patch availability and apply firmware updates promptly once released. Additionally, consider network segmentation to isolate vulnerable devices from critical infrastructure. Conduct regular security assessments and penetration tests to verify the effectiveness of mitigations. Educate network administrators about this vulnerability and the importance of timely remediation.