CVE-2025-5681 is an authorization bypass vulnerability identified in Turtek Software's Eyotek product, affecting versions prior to 23.06.2025. The vulnerability is classified under CWE-639, which relates to authorization bypass through user-controlled keys. Specifically, this flaw allows an attacker to exploit trusted identifiers within the Eyotek system, effectively bypassing authorization controls. The vulnerability can be triggered remotely (AV:N) with low attack complexity (AC:L), does not require privileges (PR:N), but requires user interaction (UI:R). The scope is unchanged (S:U), and the impact is high on confidentiality (C:H), with no impact on integrity (I:N) or availability (A:N). This means an attacker can gain unauthorized access to sensitive information without altering data or disrupting service. The vulnerability has a CVSS v3.1 base score of 6.5, indicating a medium severity level. No known exploits are currently reported in the wild, and no patches have been released yet. The vulnerability's root cause lies in improper authorization checks where user-controlled keys are trusted without sufficient validation, allowing attackers to impersonate or escalate privileges by manipulating these keys. Eyotek is a software product by Turtek Software, likely used in identity or biometric-related applications given the product name, which suggests the potential for sensitive personal data exposure if exploited.

For European organizations, the impact of CVE-2025-5681 could be significant, especially for those relying on Eyotek for identity management, biometric authentication, or access control systems. Unauthorized access to sensitive personal or organizational data could lead to breaches of GDPR regulations, resulting in legal penalties and reputational damage. Confidentiality breaches could expose personal identifiable information (PII), biometric data, or other sensitive credentials, undermining trust in security systems. Since the vulnerability does not affect integrity or availability, operational disruption is unlikely; however, the unauthorized disclosure of confidential data alone poses a serious risk. Organizations in sectors such as government, healthcare, finance, and critical infrastructure that use Eyotek or integrate it into their identity verification workflows are particularly at risk. The requirement for user interaction suggests phishing or social engineering could be vectors for exploitation, increasing the risk profile in environments with less user security awareness.

Given the absence of an official patch, European organizations should implement compensating controls immediately. These include: 1) Restricting access to Eyotek systems to trusted networks and users through network segmentation and strict access controls. 2) Enhancing monitoring and logging around Eyotek authentication and authorization events to detect anomalous access patterns indicative of exploitation attempts. 3) Conducting user training to reduce susceptibility to social engineering or phishing attacks that could trigger the user interaction requirement. 4) Applying application-layer filtering or web application firewalls (WAFs) to detect and block suspicious requests manipulating user-controlled keys. 5) Engaging with Turtek Software for early access to patches or workarounds and planning for prompt deployment once available. 6) Reviewing and hardening the configuration of Eyotek to minimize exposure of trusted identifiers and enforce strict validation of authorization tokens. 7) Considering temporary alternative authentication mechanisms or multi-factor authentication overlays to reduce reliance on vulnerable components.