Critical Cisco Security Flaw: What You Need to Know

In a recent update, Cisco addressed a significant security vulnerability affecting its Identity Services Engine (ISE). This flaw poses a serious risk as it enables unauthorized users to potentially execute harmful actions on vulnerable systems.

Understanding the Vulnerability

The vulnerability is identified as CVE-2025-20286, which carries a high CVSS score of 9.9 out of 10. This severity rating highlights the potential implications if the flaw is exploited. Cisco described it as a static credential vulnerability, emphasizing the danger associated with its existence in various cloud deployments.

What Could Happen?

According to Cisco’s advisory, this issue impacts ISE installations on major cloud platforms like Amazon Web Services (AWS), Microsoft Azure, and Oracle Cloud Infrastructure (OCI). If exploited, attackers could gain access to sensitive data, perform limited administrative tasks, modify configurations, and even disrupt service continuity. Cisco has confirmed that they are aware of a proof-of-concept (PoC) exploit, although there have been no reports of it being actively used in the wild.

How the Flaw Occurred

The root cause of this security breach lies in how credentials are generated during the deployment of Cisco ISE on cloud systems. It turns out that improper credential generation results in multiple deployments sharing common credentials, provided that they are built on the same software version and cloud platform.

To illustrate, each instance of Cisco ISE release 3.1 on AWS shares the same static credentials. However, credentials for release 3.1 will not work for release 3.2, even within the same cloud environment. Moreover, releases across different platforms will also fail to share credentials, adding another layer of complexity.

Potential Exploitation

If an attacker successfully exploits this vulnerability, they could extract user credentials from one Cisco ISE deployment and use them to access other ISE installations within unsecured ports across various cloud platforms. This could lead to unauthorized access to data, limited administrative control, and disruptions in service, but importantly, the vulnerability only affects systems where the Primary Administration node is cloud-based. On-premises installations remain unaffected.

Affected Versions

Cisco has outlined the specific versions of ISE that are susceptible to this vulnerability. The affected releases include:

• AWS: Cisco ISE versions 3.1, 3.2, 3.3, and 3.4
• Azure: Cisco ISE versions 3.2, 3.3, and 3.4
• OCI: Cisco ISE versions 3.2, 3.3, and 3.4

Recommended Actions

At present, Cisco has indicated that there are no workarounds to mitigate the risk associated with CVE-2025-20286. However, the company recommends users take immediate action by restricting traffic to only authorized administrators. Another option is to execute the command "application reset-config ise", which resets user passwords. It’s crucial to note that this command will restore Cisco ISE to its factory settings.

Conclusion

With the identified vulnerabilities in Cisco’s Identity Services Engine, the importance of cybersecurity cannot be overstated. Organizations utilizing these systems should act swiftly to secure their environments, especially on cloud platforms. Keeping software updated and following best practices in security management are fundamental steps to protect sensitive data and maintain operational integrity. For ongoing updates and information, keep an eye on Cisco’s advisories and implement the recommended actions to safeguard your systems.