CVE-2025-66176 identifies a stack overflow vulnerability in the Search and Discovery feature of the Hikvision DS-K1T331 access control device. This flaw arises from improper handling of network packets during the device’s discovery process, allowing an attacker on the same local area network to send specially crafted packets that overflow the stack. This overflow can cause the device to malfunction, potentially leading to denial of service or enabling further exploitation such as arbitrary code execution, depending on the device’s internal protections. The vulnerability affects firmware versions below V3.7.80 and does not require any authentication or user interaction, making it easier to exploit within a LAN environment. The CVSS v3.1 score of 8.8 (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) indicates a high-severity issue with low attack complexity and no privileges or user interaction needed. The vulnerability is classified under CWE-121 (Stack-based Buffer Overflow), a common and dangerous software flaw. No patches or exploits are currently publicly available, but the risk remains significant due to the critical role of access control devices in physical security and networked environments. The device’s exposure to internal networks makes it a prime target for attackers seeking to disrupt physical security or gain further network footholds.

The exploitation of this vulnerability can have severe consequences for organizations relying on Hikvision DS-K1T331 devices for access control. A successful attack can cause device malfunction or denial of service, potentially disabling physical access controls and compromising facility security. The high impact on confidentiality, integrity, and availability means attackers could disrupt security monitoring, manipulate access logs, or use the compromised device as a pivot point for lateral movement within the network. This can lead to unauthorized physical access, data breaches, and operational disruptions. Organizations in critical infrastructure sectors, government, finance, and large enterprises that deploy these devices extensively are particularly at risk. The requirement for attacker presence on the LAN limits remote exploitation but does not eliminate risk, especially in environments with weak network segmentation or insider threats. The absence of known exploits in the wild currently reduces immediate risk but does not preclude future exploitation once details become widely known.

To mitigate this vulnerability, organizations should implement the following specific measures: 1) Immediately inventory all Hikvision DS-K1T331 devices and verify firmware versions, prioritizing upgrades to V3.7.80 or later once patches are released. 2) Until patches are available, restrict device network access by segmenting the LAN to isolate access control devices from general user networks and untrusted devices. 3) Employ network access controls such as VLANs, ACLs, and firewall rules to limit communication to and from these devices strictly to authorized management stations. 4) Monitor network traffic for unusual or malformed packets targeting the device’s discovery protocol, using IDS/IPS solutions tuned for Hikvision device signatures. 5) Implement strict physical and logical access controls to reduce insider threat risks. 6) Coordinate with Hikvision support for official patches and security advisories. 7) Conduct regular security assessments and penetration tests focusing on physical security infrastructure to detect potential exploitation attempts. These targeted steps go beyond generic advice by focusing on network segmentation, traffic monitoring, and proactive device management tailored to the vulnerability’s characteristics.