CVE-2025-12266 is a remote code injection vulnerability affecting Zytec Dalian Zhuoyun Technology's Central Authentication Service (CAS) up to version 20251009. The vulnerability resides in the _empty function located in the /index.php/auth/widget endpoint. Specifically, the parameters get.layer, get.widget, and get.action can be manipulated by an unauthenticated remote attacker to inject and execute arbitrary code on the server. This occurs because the application fails to properly sanitize or validate these input parameters before processing, allowing malicious payloads to be executed within the context of the web server. The vulnerability does not require any authentication or user interaction, making it highly accessible to attackers. The vendor was notified early but has not issued any patches or advisories, and the exploit code has been made publicly available, increasing the risk of exploitation. The CVSS 4.0 base score is 5.3, indicating a medium severity level due to the combination of network attack vector, low attack complexity, no privileges or user interaction required, but limited impact on confidentiality, integrity, and availability. The vulnerability could lead to unauthorized code execution, potentially allowing attackers to compromise authentication mechanisms, escalate privileges, or move laterally within affected networks. Given the critical role of CAS in managing user authentication and access control, exploitation could have significant security implications.

For European organizations, exploitation of CVE-2025-12266 could result in unauthorized remote code execution on critical authentication infrastructure, leading to potential compromise of user credentials, session hijacking, and unauthorized access to sensitive systems. This could disrupt authentication services, causing denial of service or enabling further attacks such as privilege escalation and lateral movement within corporate networks. Organizations relying on Zytec's CAS for single sign-on or centralized authentication are particularly at risk, as attackers could bypass security controls or implant persistent backdoors. The lack of vendor response and available patches increases exposure time, making timely mitigation essential. Additionally, regulatory requirements such as GDPR impose strict obligations on protecting authentication systems and personal data, so exploitation could lead to compliance violations and reputational damage. The medium CVSS score reflects moderate but tangible risks, especially in environments where authentication services are critical to operational security.

Given the absence of official patches, European organizations should implement immediate compensating controls. First, restrict external access to the vulnerable CAS endpoints by enforcing network-level controls such as firewalls or VPNs to limit exposure only to trusted internal users. Employ web application firewalls (WAFs) with custom rules to detect and block suspicious parameter manipulations targeting get.layer, get.widget, and get.action. Conduct thorough input validation and sanitization on any proxy or gateway layers if possible. Monitor logs for unusual requests or error patterns indicative of exploitation attempts. Consider deploying intrusion detection/prevention systems (IDS/IPS) tuned to detect known exploit signatures. If feasible, isolate the CAS server in a segmented network zone to limit lateral movement in case of compromise. Prepare incident response plans for rapid containment and recovery. Engage with Zytec for updates and consider alternative authentication solutions if the vendor remains unresponsive. Finally, ensure all other systems and software are up to date to reduce overall attack surface.