Critical Cisco ISE Vulnerability Under Active Attack: What You Need to Do Now
Network administrators and security professionals must take immediate action to address a critical vulnerability in Cisco’s Identity Services Engine (ISE) that is now being actively exploited by attackers. This security flaw can allow a remote attacker to gain complete administrative control over the system, posing a significant threat to enterprise network security.
Cisco ISE is a foundational security product used by organizations worldwide to enforce security policies, control network access, and manage user and device identities. A compromise of this system can have far-reaching consequences, effectively dismantling a core layer of an organization’s defense.
Understanding the Threat: The Cross-Site Scripting (XSS) Flaw
The vulnerability, tracked as CVE-2022-20864, is a persistent cross-site scripting (XSS) flaw found in the web-based management interface of Cisco ISE. This type of flaw allows an attacker to inject malicious scripts into web pages viewed by other users. In this specific case, the vulnerability exists in a component that fails to properly validate user-supplied input.
The attack vector is straightforward but devastating. An unauthenticated, remote attacker can craft a specific HTTP request and send it to the targeted ISE device. If a legitimate administrator later views the manipulated information on the management portal, the malicious script will execute within their browser.
The Impact: Complete Administrative Takeover
The primary danger of this exploit is its ability to steal sensitive session information.
Session Cookie Theft: The most immediate risk is that an attacker can leverage this flaw to steal the active session cookie of a legitimate administrator. This cookie is a small piece of data that the server uses to keep a user logged in.
Administrator Impersonation: With this stolen cookie, the attacker can impersonate the administrator, gaining full and authenticated access to the ISE administration portal.
Once an attacker has administrative control, they can perform any action available to a legitimate admin. This includes changing security policies, adding unauthorized users or devices, disabling security controls, and exfiltrating sensitive network data. Essentially, they can take complete control of the network’s central nervous system for access control.
This is not a theoretical threat; active exploitation has been confirmed. A public proof-of-concept (PoC) exploit has been released, making it easier for threat actors to weaponize this vulnerability against unpatched systems.
Immediate Steps to Mitigate the Threat
Given the severity of this vulnerability and the evidence of active attacks, swift remediation is essential.
Identify Affected Versions: The vulnerability affects multiple versions of Cisco ISE. It is crucial to check your current deployment against Cisco’s official security advisory to determine if your systems are at risk.
Apply Security Patches: The most critical step is to apply the security patches provided by Cisco immediately. Cisco has released software updates that address this vulnerability. Delaying this process leaves your network exposed to a known and active threat.
Restrict Management Access: As a best practice, access to the ISE management interface should be strictly controlled. Ensure that the management portal is not exposed to the public internet and is only accessible from a secure, internal management network or via a VPN with multi-factor authentication.
Proactive Security Best Practices for Cisco ISE
Beyond applying this specific patch, organizations should use this opportunity to harden their overall security posture.
- Monitor Logs: Actively monitor ISE logs for any suspicious activity or unexpected administrative actions. Look for signs of unauthorized configuration changes or logins from unusual locations.
- Enforce MFA: If you haven’t already, enforce Multi-Factor Authentication (MFA) for all administrative accounts. Even if an attacker steals a session cookie, MFA can provide an additional layer of protection against unauthorized access.
- Principle of Least Privilege: Ensure that administrative accounts are configured with the minimum level of privilege necessary to perform their duties. Avoid using a single, all-powerful account for daily tasks.
- Network Segmentation: A well-segmented network can help contain the blast radius of a potential compromise. Ensure your ISE deployment is properly segmented from other parts of the network to limit lateral movement by an attacker.
Protecting your Cisco ISE deployment is paramount. The vulnerability identified in CVE-2022-20864 presents a clear and present danger to network integrity. Patching is not optional—it is an urgent requirement to protect your network infrastructure from a complete takeover.
Source: https://www.helpnetsecurity.com/2025/07/23/maximum-severity-cisco-ise-vulnerabilities-exploited-by-attackers/
