CVE-2025-20285 is a medium-severity vulnerability affecting Cisco Identity Services Engine (ISE) software versions 3.1.0 through 3.4 Patch 1 and various patches in between. The vulnerability resides in the IP Access Restriction feature, which is designed to limit administrative access to the device based on source IP addresses. Due to improper enforcement of these access controls, an authenticated attacker with valid administrative credentials can bypass the configured IP restrictions and log in to the device from an unauthorized IP address. This occurs because the system assumes certain data (IP access restriction parameters) to be immutable or properly enforced, but in reality, these controls can be circumvented. The vulnerability requires the attacker to have administrative privileges, so it is not exploitable by unauthenticated users. The CVSS 3.1 base score is 4.1, reflecting a medium severity primarily due to the requirement for high privileges and no impact on confidentiality or availability, but with a potential integrity impact. The scope is changed (S:C), meaning the vulnerability affects components beyond the initially vulnerable component. Exploitation does not require user interaction, and the attack vector is network-based. No known exploits are currently reported in the wild. The vulnerability could allow an attacker to perform administrative actions from disallowed IP addresses, potentially evading network-based access controls and monitoring systems that rely on IP restrictions for security enforcement. This could facilitate further malicious activity or persistence within the network infrastructure managed by Cisco ISE.

For European organizations, this vulnerability poses a risk primarily to network security and administrative control integrity. Cisco ISE is widely used in enterprise environments for network access control, policy enforcement, and device profiling. Bypassing IP access restrictions could allow attackers with stolen or otherwise obtained administrative credentials to access the management interface from unauthorized locations, increasing the risk of lateral movement, unauthorized configuration changes, or deployment of malicious policies. This could undermine network segmentation and security policies critical for compliance with regulations such as GDPR and NIS Directive. The impact is heightened in sectors with stringent security requirements, such as finance, healthcare, and critical infrastructure, where Cisco ISE is often deployed. Although the vulnerability does not directly impact confidentiality or availability, the integrity of network access controls is compromised, potentially leading to indirect data breaches or service disruptions through misconfiguration or malicious policy enforcement.

1. Immediately audit and restrict administrative credentials to minimize the number of users with high privileges on Cisco ISE systems. 2. Implement multi-factor authentication (MFA) for all administrative access to reduce the risk of credential misuse. 3. Monitor and log all administrative access attempts, especially those originating from IP addresses outside the expected range, to detect anomalous access patterns. 4. Apply network segmentation and firewall rules to limit access to Cisco ISE management interfaces strictly to trusted IP addresses and management networks, adding an additional layer beyond the IP Access Restriction feature. 5. Stay updated with Cisco security advisories and apply patches or updates as soon as they become available to remediate this vulnerability. 6. Consider deploying intrusion detection/prevention systems (IDS/IPS) tuned to detect unusual administrative access behaviors. 7. Conduct regular security assessments and penetration testing focusing on administrative access controls to verify the effectiveness of implemented mitigations.