Critical Cisco ISE Auth Bypass Flaw Impacts Cloud Deployments on AWS, Azure, and OCI (CVE-2025-20286)

Introduction

On June 5, 2025, Cisco released a critical security patch to address a vulnerability in its Identity Services Engine (ISE), which could have serious implications for cloud deployments on platforms like Amazon Web Services (AWS), Microsoft Azure, and Oracle Cloud Infrastructure (OCI). This vulnerability, tracked as CVE-2025-20286, has been assigned a CVSS score of 9.9 out of 10, indicating its severity.

If exploited, CVE-2025-20286 could allow unauthenticated attackers to gain access to sensitive data, modify system configurations, perform limited administrative operations, or disrupt services within affected systems. While Cisco has patched the flaw, it is critical that all users of Cisco ISE on cloud platforms update their systems immediately to avoid potential risks.

What Is CVE-2025-20286?

CVE-2025-20286 is a critical vulnerability in Cisco’s Identity Services Engine (ISE) that stems from the improper generation of credentials when Cisco ISE is deployed in cloud environments such as AWS, Azure, and OCI. The flaw allows unauthenticated remote attackers to bypass authentication and gain unauthorized access to sensitive data or execute unauthorized actions, which could lead to significant service disruptions.

The issue lies in the fact that static credentials are generated for Cisco ISE instances deployed on cloud platforms, which makes them vulnerable to exploitation. If attackers are able to access one instance of Cisco ISE in the cloud, they could use the same credentials to access instances deployed in different environments, provided they share the same software release and cloud platform.

Severity and Impact

The flaw has been given a CVSS score of 9.9, classifying it as a critical vulnerability. It can be exploited remotely and does not require any authentication. This makes CVE-2025-20286 a high-risk vulnerability for organizations that use Cisco ISE to manage access to their network infrastructure.

Successful exploitation could allow attackers to:

• Access sensitive data stored in Cisco ISE deployments.
• Execute limited administrative operations within the system.
• Modify system configurations to potentially disable security features or cause operational disruptions.
• Disrupt services, impacting the availability of network access control for the affected systems.

This issue is particularly concerning for organizations using Cisco ISE in the cloud (on AWS, Azure, or OCI) because the vulnerability allows attackers to access instances across cloud environments using the same credentials.

How Does CVE-2025-20286 Work?

The CVE-2025-20286 vulnerability is rooted in the way Cisco ISE generates and handles static credentials when deployed on cloud platforms. These credentials are platform-specific and release-specific, meaning each version of Cisco ISE on a particular platform uses a unique set of credentials. However, the flaw occurs because the same set of static credentials is used across all instances of Cisco ISE that share the same release and cloud platform.

For example:

• Release 3.1 of Cisco ISE deployed on AWS will have the same static credentials for all instances.
• Release 3.2 of Cisco ISE deployed on AWS will have a different set of credentials from Release 3.1 on AWS but would share the same credentials across AWS instances.
• However, Release 3.2 on AWS will have different credentials from Release 3.2 on Azure.

This lack of diversity in credentials across deployments makes it easier for attackers to exploit instances in one cloud environment and potentially pivot to others with the same credentials.

Successful Exploitation of CVE-2025-20286

Once an attacker gains access to a CVE-2025-20286-vulnerable Cisco ISE deployment, they can:

1. Extract user credentials: By exploiting the vulnerability, attackers can extract user credentials from the cloud-based Cisco ISE instance.
2. Access other cloud deployments: Using the same credentials, attackers can attempt to access other Cisco ISE instances in different cloud environments, such as AWS, Azure, or OCI.
3. Perform unauthorized actions: The attacker can modify configurations, potentially disabling authentication mechanisms, or carry out service disruptions by altering or deleting system files.

What Systems Are Affected by CVE-2025-20286?

CVE-2025-20286 affects Cisco ISE deployments in cloud environments on the following platforms:

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

The vulnerability specifically impacts systems where the Primary Administration Node (PAN) is deployed in the cloud. Cisco ISE deployments that have their Primary Administration Node on-premises are not affected by this vulnerability.

Impact on Cloud Deployments

The risk is highest for organizations that run Cisco ISE on cloud-based platforms since the flaw allows for remote exploitation, enabling attackers to move laterally across environments. Attackers exploiting this flaw can perform a wide range of malicious activities, including unauthorized access, service disruption, and system configuration changes.

Not Affected: On-Premises Deployments

Organizations that deploy Cisco ISE on-premises (with the Primary Administration Node hosted on their internal infrastructure) are not impacted by this specific vulnerability. The issue is isolated to cloud deployments, as it arises from the way credentials are handled in those environments.

Mitigation: What Should You Do?

Apply the Security Patch Immediately: The most important step is to apply the latest patch provided by Cisco. This patch addresses CVE-2025-20286 and mitigates the security flaw by correcting the static credential issue and ensuring that each instance of Cisco ISE has unique, secure credentials.

• Cisco ISE Version 3.2 or later, which includes the security patch, should be deployed immediately to avoid potential exploitation.

Restrict Access to Cisco ISE: As a temporary mitigation measure, organizations should consider restricting access to Cisco ISE instances in AWS, Azure, and OCI until the patch has been applied. This can help prevent unauthorized access while administrators implement the fix.

Monitor for Suspicious Activity: Organizations should closely monitor their Cisco ISE deployments for any unusual activity, such as unauthorized login attempts or changes to system configurations. This can help detect if the vulnerability is being actively exploited.

Vulert: Real-Time Vulnerability Monitoring for Cloud Environments

For organizations looking to stay ahead of vulnerabilities like CVE-2025-20286, Vulert provides real-time vulnerability monitoring. Vulert helps organizations quickly identify and respond to vulnerabilities that impact their infrastructure, especially in cloud environments such as AWS, Azure, and OCI.

Vulert’s Key Features:

1. Real-Time Alerts: Vulert sends instant notifications when vulnerabilities like CVE-2025-20286 are disclosed, allowing organizations to take immediate action.
2. Comprehensive CVE Database: Vulert offers a detailed database of vulnerabilities, including CVE-2025-20286, with recommendations for remediation.
3. Automated Scanning: Vulert automates the process of scanning cloud deployments, ensuring that security patches are applied in a timely manner.
4. Actionable Reports: Vulert provides detailed reports with actionable steps to mitigate vulnerabilities.

Conclusion

CVE-2025-20286 is a critical vulnerability that impacts Cisco ISE deployments in cloud environments such as AWS, Azure, and OCI. If exploited, it can lead to unauthorized access, data breaches, and service disruptions. To mitigate the risk, organizations should apply the security patch released by Cisco and monitor their cloud environments for any suspicious activity.

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