CVE-2025-20286 Credential Reuse Vulnerability in Cisco ISE

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CVE-2025-20286 is a critical security vulnerability identified in Cisco Identity Services Engine (ISE) when deployed on certain cloud platforms, including:

• Amazon Web Services (AWS)
• Microsoft Azure
• Oracle Cloud Infrastructure (OCI)

This vulnerability stems from a flawed credential generation process that occurs during the deployment of Cisco ISE in cloud environments. Due to this flaw, multiple instances of Cisco ISE may be deployed with identical, static credentials—a dangerous condition that violates fundamental principles of secure system design, such as uniqueness and isolation of administrative access.

Severity & Exploitability

• CVSS v3.1 Base Score: 9.9 / 10 (Critical)
• Attack Vector: Network (Remote)
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Changed (affects resources beyond the vulnerable component)
• Confidentiality: Low
• Integrity: Low
• Availability: High

Summary: An attacker with no prior access or credentials can remotely exploit this vulnerability to gain unauthorized access to affected Cisco ISE systems. This includes the ability to read sensitive data, make configuration changes, perform limited administrative actions, or disrupt critical services. Given the ease of exploitation and breadth of impact, this vulnerability poses a severe threat to enterprise network environments using Cisco ISE in the cloud.

Technical Details

At the core of CVE-2025-20286 is Cisco’s improper handling of initial administrative credentials during the ISE deployment process in supported cloud environments. In certain versions, these credentials are hardcoded or predictably generated, resulting in identical login details across multiple independent deployments.

This security lapse allows a remote, unauthenticated attacker to leverage a single known credential set to compromise a wide range of Cisco ISE instances hosted on cloud platforms—regardless of organizational boundaries. In effect, it creates a shared backdoor that can be used to compromise systems at scale.

Affected Versions

The vulnerability affects Cisco ISE software versions deployed in the cloud (not on-prem) as follows: Version Patch Levels Affected 3.0.0 Patches 1 through 8 3.1.0 Patches 1 through 10 3.2.0 Base and Patches 1–7 3.3.0 Base and Patches 1–5 3.4.0 Base and Patch 1

❗ Only deployments where the Primary Administration Node (PAN) is hosted in the cloud are vulnerable. On-premises Cisco ISE deployments are not affected.

Threat Scenarios & Impact

1. Mass Compromise: One credential set may allow attackers to access multiple organizations’ Cisco ISE portals.
2. Service Disruption: Attackers can disable policy services, authentication systems, or authorization rules—crippling enterprise access control.
3. Privilege Abuse: Attackers may escalate privileges within the ISE admin interface, leading to further internal compromise.
4. Policy Manipulation: Misconfigured or malicious policies can be injected to allow unauthorized access or data exfiltration.

Mitigation & Response

Cisco’s official recommendation is to immediately upgrade to fixed software versions and rotate any credentials generated as part of an affected deployment.

✔️ Actions to Take Now:

1. Patch Immediately
   • Cisco has released updates that address the credential reuse issue. Apply all relevant patches for your ISE version and cloud environment.
2. Regenerate Administrative Credentials
   • Manually create new, unique credentials for each cloud deployment of Cisco ISE.
   • Remove any default or repeated login credentials that may have been automatically configured.
3. Implement Strong Access Controls
   • Limit external access to ISE’s administrative interfaces using security groups, firewalls, or VPN-based access.
   • Require multi-factor authentication (MFA) for all administrative logins.
4. Monitor for Unauthorized Access
   • Audit access logs for unusual login attempts or administrative actions.
   • Set up automated alerts for anomalous activity within the ISE system.
5. Consider Deployment Architecture
   • If possible, consider shifting the Primary Administration Node (PAN) from the cloud to a more secure on-premises environment.

Final Thoughts

CVE-2025-20286 exemplifies how cloud misconfigurations—especially around automation and credential management—can introduce systemic vulnerabilities across distributed environments. Given the criticality of Cisco ISE in network access control, immediate patching and proactive hardening are essential to prevent a potentially devastating compromise.

If your organization runs Cisco ISE in the cloud, treat this as a top-priority incident and coordinate with your security and infrastructure teams to verify that all deployments are patched, isolated, and audited.