CVE-2025-20305 is a vulnerability identified in Cisco Identity Services Engine (ISE) software, specifically within its web-based management interface. The root cause is insufficient granularity in access control mechanisms, where certain files and data elements lack proper protection. This flaw allows an attacker who has authenticated with read-only administrator privileges to perform actions that reveal sensitive information, such as passwords, which should only be visible to higher-privileged users. The vulnerability affects a broad range of Cisco ISE versions from 3.1.0 through 3.4 Patch 1, including multiple patch releases. The attack vector is remote network access with low attack complexity and no user interaction required. The CVSS v3.1 base score is 4.3, reflecting a medium severity primarily due to confidentiality impact without affecting integrity or availability. Although no exploits are known in the wild, the exposure of credential information could enable lateral movement or privilege escalation in compromised environments. Cisco ISE is widely used for network access control and policy enforcement, making this vulnerability significant for organizations relying on it for secure network segmentation and identity management.

For European organizations, the confidentiality breach posed by this vulnerability could lead to unauthorized disclosure of sensitive credentials, undermining network access controls and potentially enabling attackers to escalate privileges or move laterally within corporate networks. This is particularly critical for sectors such as finance, telecommunications, energy, and government, where Cisco ISE is commonly deployed to enforce strict network policies. Exposure of passwords could facilitate further attacks including unauthorized access to critical systems, data exfiltration, or disruption of services indirectly. Although the vulnerability does not directly affect system integrity or availability, the compromise of sensitive information can have cascading effects on overall security posture and compliance with data protection regulations like GDPR. Organizations with large-scale Cisco ISE deployments should consider this a significant risk to their identity and access management infrastructure.

Organizations should immediately identify and inventory all Cisco ISE instances running affected versions (3.1.0 through 3.4 Patch 1). Cisco is expected to release patches or updates addressing this vulnerability; applying these updates promptly is the most effective mitigation. Until patches are applied, organizations should restrict read-only administrator privileges to only trusted personnel and monitor for unusual access patterns or attempts to retrieve sensitive information. Implement network segmentation to limit access to the Cisco ISE management interface, ideally restricting it to dedicated management networks or VPNs. Enable and review detailed logging and alerting on administrative actions within Cisco ISE to detect potential exploitation attempts. Additionally, conduct regular audits of user roles and permissions to ensure least privilege principles are enforced. If possible, deploy multi-factor authentication (MFA) for all administrative access to reduce the risk of credential compromise. Finally, consider compensating controls such as network intrusion detection systems (NIDS) tuned to detect anomalous activity targeting Cisco ISE.