CVE-2025-22391 is an escalation of privilege vulnerability affecting SigTest software versions before 6.1.10. The root cause is improper access control enforcement within Ring 3 user applications, which operate in user mode. This flaw allows an adversary with low privileges and authenticated access to escalate their privileges, potentially gaining higher-level access within the application context. The attack requires local access, meaning the attacker must have some foothold on the system, and also requires active user interaction, such as executing a specific action or input. The attack complexity is high, indicating that exploitation is non-trivial and may require detailed knowledge of the system's behavior or specific conditions to succeed. The vulnerability impacts confidentiality, integrity, and availability at a high level within the vulnerable application, but does not propagate to the entire system's confidentiality, integrity, or availability. The CVSS 4.0 base score is 5.4, reflecting medium severity, with attack vector local, attack complexity high, privileges required low, and user interaction required. No known exploits have been reported in the wild as of the publication date. The vulnerability underscores the importance of strict access control mechanisms within user-mode applications to prevent privilege escalation attacks that could compromise sensitive data or disrupt application functionality.

For European organizations, this vulnerability poses a risk primarily to environments where SigTest is deployed, particularly if older versions prior to 6.1.10 are in use. The escalation of privilege could allow attackers with limited access to gain elevated privileges, potentially leading to unauthorized access to sensitive data or disruption of critical testing or validation processes managed by SigTest. This could impact confidentiality, integrity, and availability of the affected application, which may be critical in regulated industries such as finance, healthcare, or manufacturing where SigTest might be used for software validation or compliance testing. Although the vulnerability requires local access and user interaction, insider threats or compromised endpoints could exploit this to move laterally or escalate privileges within the network. The medium severity score suggests a moderate risk, but the potential for high impact on confidentiality, integrity, and availability within the application context means organizations should not underestimate the threat. The absence of known exploits in the wild provides a window for proactive mitigation before exploitation becomes widespread.

European organizations should immediately inventory their SigTest deployments to identify versions prior to 6.1.10. Applying the latest available patches or upgrading to version 6.1.10 or later is the most effective mitigation. In the absence of patches, organizations should enforce strict local access controls and limit authenticated user privileges to the minimum necessary. Implementing endpoint security measures to detect and prevent unauthorized local access or suspicious user interactions can reduce exploitation risk. User training to recognize and avoid actions that could trigger exploitation is advisable given the requirement for active user interaction. Monitoring and logging user activities on systems running SigTest can help detect attempts to exploit this vulnerability. Network segmentation can limit the impact of a compromised endpoint. Finally, organizations should stay alert for any emerging exploit reports and be prepared to respond swiftly.