Introduction

On June 4, 2025, Cisco released a security advisory disclosing a critical vulnerability affecting its Identity Services Engine (ISE), identified as CVE-2025-20286. This vulnerability received a CVSS score of 9.9 (out of 10), classifying it as critical due to its ability to be exploited remotely without authentication and the availability of public Proof-of-Concept (PoC) code, which has drawn widespread attention. This article provides a detailed analysis of CVE-2025-20286, including its cause, impact, exploitation methods, and mitigation measures.

Vulnerability Overview

1. Vulnerability Details

CVE ID: CVE-2025-20286
Disclosure Date: June 4, 2025
CVSS Score: 9.9/10 (Critical)
Affected Products: Cisco Identity Services Engine (ISE) deployments on AWS, Microsoft Azure, and Oracle Cloud Infrastructure (OCI)
Vulnerability Type: Static Credential Vulnerability
Attack Vector: Remote, no authentication required
Exploitation Status: No evidence of in-the-wild exploitation, but public PoC code is available

2. Vulnerability Description

CVE-2025-20286 stems from improper generation of static credentials in Cisco ISE deployments on cloud platforms (AWS, Azure, OCI). Cisco ISE is a platform used for network access control and identity management, widely adopted in enterprise environments. However, a flaw in the credential generation mechanism during cloud deployment results in multiple ISE instances running the same software version and cloud platform sharing identical static credentials. This means that if an attacker obtains credentials from one ISE instance, they can use the same credentials to access other ISE instances running the same version and platform.

Root Cause

During cloud deployment of ISE, the system automatically generates a set of static credentials (username and password) for management access. These credentials are identical across all instances of the same software version and cloud platform, and they are not properly isolated.
Scope of Impact: This vulnerability affects only ISE instances where the Primary Administration Node (PAN) is deployed in the cloud. On-premises deployments are not affected.

Attack Consequences

Attackers can exploit this vulnerability remotely without authentication, potentially leading to:

  • Sensitive Data Exposure: Access to configuration files, user data, or other sensitive information.
  • Limited Administrative Operations: Performing certain management functions, such as modifying system settings.
  • Configuration Tampering: Altering network access policies or service configurations.
  • Service Disruption: Disrupting ISE functionality through configuration changes or denial-of-service attacks.

Technical Details

1. Cause of the Vulnerability

The root issue of CVE-2025-20286 lies in the static credential generation mechanism in Cisco ISE cloud deployments. Specifically:

  • When ISE is deployed on AWS, Azure, or OCI, the system generates a default set of static credentials for management access.
  • These credentials are identical across all instances of the same software version (e.g., ISE 3.1, 3.2, 3.3, 3.4) on the same cloud platform.
  • Attackers can obtain these credentials through reverse engineering, leaked configuration files, or other means and use them to access other organizations’ ISE instances running the same version and platform.
  • The credentials are not properly isolated or dynamically generated, allowing cross-instance exploitation.

2. Exploitation Methods

The steps for exploiting CVE-2025-20286 are as follows:

Obtaining Credentials

Attackers may acquire static credentials through:

  • Reverse engineering a cloud-deployed ISE instance to extract credentials from configuration files.
  • Exploiting leaked backup files or logs that may contain unencrypted credentials.
  • Using publicly available PoC code to test known default credentials.

Identifying Targets

Attackers scan for ISE instances running affected versions (3.0, 3.1, 3.2, 3.3, 3.4) on AWS, Azure, or OCI. Since credentials are universal across the same version and platform, attackers do not need to tailor attacks to specific targets.

Remote Access

Attackers use the obtained credentials to log into target ISE instances via unprotected ports (typically HTTP/HTTPS management ports), bypassing standard authentication processes due to the no-authentication-required nature of the vulnerability.

Malicious Actions

  • Access Sensitive Data: Retrieve user identity information or network policies.
  • Modify Configurations: Alter access control lists (ACLs) or authentication policies.
  • Disrupt Services: Delete critical configurations to impair ISE functionality.

3. Impact of PoC Code

On June 5, 2025, security researchers published PoC code for CVE-2025-20286, further lowering the barrier to exploitation. Even attackers with limited technical skills can use these scripts to launch attacks. The PoC code typically includes:

  • Scripts to extract static credentials.
  • Tools to scan for cloud-based ISE instances.
  • Automated processes for unauthorized access using the credentials.
    While no widespread exploitation has been reported, the public availability of PoC code increases the likelihood of malicious activity.

Affected Versions and Fixes

1. Affected Versions

The following Cisco ISE versions are affected by CVE-2025-20286 when deployed on AWS, Azure, or OCI:

  • Cisco ISE 3.0.0
  • Cisco ISE 3.0.0 p1
  • Cisco ISE 3.0.0 p2
  • Cisco ISE 3.1
  • Cisco ISE 3.2
  • Cisco ISE 3.3 (below 3.3P8)
  • Cisco ISE 3.4 (below 3.4P3)

Note: Only instances with the Primary Administration Node (PAN) deployed in the cloud are affected. On-premises ISE instances are not vulnerable.

2. Fixes

Cisco has released patches to address CVE-2025-20286, including:

  • Patch Updates:
    • ISE 3.3: Upgrade to 3.3P8 or higher.
    • ISE 3.4: Upgrade to 3.4P3 or higher.
    • ISE 3.5: Full fix scheduled for August 2025.
  • Hotfix Patch: Cisco provides a hotfix (ise-apply-CSCwn63400_3.1.x_patchall-SPA.tar.gz) for versions 3.1 to 3.4.

Official Fix Link: Cisco Security Advisory

3. Mitigation Measures

As no direct workaround is available, Cisco recommends the following to reduce risk:

  • Restrict Access:
    • Use cloud security groups to limit access to ISE management ports to trusted IP addresses.
    • Enable IP-based access control in ISE to restrict management interface access.
  • Reset Credentials:
    • Reset default credentials on newly installed ISE instances to ensure unique credentials for each instance.
  • Monitoring and Logging:
    • Monitor ISE management interface access logs for suspicious login attempts.
    • Use Security Information and Event Management (SIEM) systems to track potential exploitation.
  • Upgrade Plan:
    • Upgrade to patched versions (3.3P8 or 3.4P3) or apply the hotfix as soon as possible.

Potential Impact and Risks

1. Impact on Enterprises

The high CVSS score (9.9) and remote, no-authentication exploitation make CVE-2025-20286 a significant threat, with potential impacts including:

  • Data Breaches: Attackers may access sensitive network access policies, user credentials, or configuration data.
  • Loss of Network Control: Modifying ISE configurations could allow unauthorized devices or users to access the network.
  • Service Disruption: Deleting critical configurations or launching denial-of-service attacks could render ISE unavailable, disrupting enterprise network operations.
  • Compliance Risks: Data breaches or unauthorized access may violate regulations like GDPR or HIPAA, leading to legal and financial consequences.

According to SOC Prime, the number of disclosed vulnerabilities in 2025 has increased by 16% compared to the previous year, reaching over 20,000. CVE-2025-20286 is one of the critical vulnerabilities, highlighting the widespread issue of misconfigured security in cloud environments. The extensive use of cloud platforms (AWS, Azure, OCI) amplifies the impact of static credential vulnerabilities, as attackers can exploit identical credentials across organizations. Additionally, Cisco products, such as ISE and IOS XE, are frequent targets due to their widespread deployment, with several Cisco-related vulnerabilities already listed in CISA’s Known Exploited Vulnerabilities (KEV) catalog.

Defense Recommendations

1. Enterprise Users

  • Immediate Assessment: Check if your organization uses affected ISE versions on AWS, Azure, or OCI with the Primary Administration Node in the cloud.
  • Apply Patches: Upgrade to patched versions (3.3P8 or 3.4P3) or apply the hotfix immediately.
  • Network Isolation: Use cloud security groups or firewall rules to restrict access to ISE management ports.
  • Monitor Anomalies: Deploy intrusion detection systems (IDS) or SIEM to monitor unauthorized access attempts to the ISE management interface.
  • Regular Audits: Periodically review ISE configurations and credentials to ensure no default or shared credentials are in use.

2. Security Teams

  • Threat Intelligence: Subscribe to Cisco security advisories or third-party threat intelligence services for updates on CVE-2025-20286.
  • PoC Monitoring: Track the spread of public PoC code to prevent exploitation using known scripts.
  • Vulnerability Scanning: Use tools like Tenable or Qualys to detect affected ISE instances in cloud environments.

3. Individual Users

While CVE-2025-20286 primarily affects enterprise environments, individual users may be indirectly impacted (e.g., through enterprise network service disruptions). Recommendations include:

  • Monitor security advisories from service providers to ensure their Cisco ISE deployments are updated.
  • Use strong passwords and multi-factor authentication (MFA) to secure personal network access.

Conclusion

CVE-2025-20286 is a critical static credential vulnerability affecting Cisco ISE deployments on AWS, Azure, and OCI. Its remote exploitation without authentication and the availability of public PoC code make it a significant target for attackers. Enterprises should promptly assess affected systems, apply patches or mitigation measures, and strengthen network access controls to reduce risks. By implementing timely fixes and proactive defenses, organizations can effectively counter this threat and prevent data breaches or service disruptions. Cybersecurity is an ongoing challenge, and staying vigilant, updating systems promptly, and maintaining proper configurations are key to protecting systems.

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Keywords: CVE-2025-20286, Security Vulnerability, Threat Intelligence, Cisco