CVE-2025-27217 is a critical Server-Side Request Forgery (SSRF) vulnerability identified in the Ubiquiti Inc UISP Application, specifically affecting version 2.4.220. SSRF vulnerabilities occur when an attacker can abuse a server to make HTTP requests to unintended locations, potentially accessing internal systems or services that are otherwise inaccessible externally. In this case, the vulnerability allows a malicious actor with certain permissions—though no authentication is required according to the CVSS vector—to craft requests that the UISP Application will execute outside its intended scope. This can lead to unauthorized access to internal network resources, potentially exposing sensitive information or enabling further attacks. The CVSS score of 9.1 (critical) reflects the high impact on confidentiality and integrity, with network attack vector, low attack complexity, no privileges required, and no user interaction needed. The vulnerability is classified under CWE-918, which pertains to SSRF issues. Although no known exploits are reported in the wild yet, the critical severity and ease of exploitation make this a significant threat. UISP (Ubiquiti Internet Service Provider) Application is used for managing network devices and infrastructure, making it a high-value target for attackers seeking to disrupt or infiltrate network operations.

For European organizations, especially those relying on Ubiquiti UISP Application version 2.4.220 for network management, this vulnerability poses a serious risk. Exploitation could allow attackers to bypass network segmentation and access internal services, potentially leading to data breaches, unauthorized configuration changes, or lateral movement within corporate networks. Given the critical nature of the vulnerability and the lack of required authentication, attackers could exploit this remotely without user interaction, increasing the risk of widespread compromise. This could impact confidentiality by exposing sensitive internal data, and integrity by allowing unauthorized modifications to network configurations. Availability impact is less direct but could occur if attackers leverage the vulnerability to disrupt network management services. The threat is particularly concerning for organizations in sectors with stringent data protection requirements such as finance, healthcare, and critical infrastructure within Europe, where regulatory compliance (e.g., GDPR) mandates robust security controls.

Immediate mitigation should focus on upgrading the UISP Application to a patched version once available from Ubiquiti. Until a patch is released, organizations should implement network-level controls to restrict access to the UISP Application management interface, limiting it to trusted IP addresses and internal networks only. Employ strict firewall rules and segmentation to prevent the UISP server from making arbitrary outbound requests, especially to internal services. Monitoring and logging of all requests made by the UISP Application should be enhanced to detect anomalous or unexpected outbound connections indicative of SSRF exploitation attempts. Additionally, review and minimize permissions granted to users within UISP to reduce the attack surface. Employ web application firewalls (WAFs) with SSRF detection capabilities to block suspicious request patterns. Regularly audit and update network device management practices to ensure adherence to the principle of least privilege and network segmentation best practices.