Overview
In the ever-evolving landscape of cybersecurity, new vulnerabilities are discovered regularly. One of these is the CVE-2025-20152, a significant vulnerability identified in the RADIUS message processing feature of Cisco Identity Services Engine (ISE). This vulnerability may allow unauthenticated remote attackers to create a denial of service (DoS) condition on an affected device, potentially leading to system compromise or data leakage, and hence, poses a significant threat to the confidentiality, integrity, and availability of data.
Given the widespread use of Cisco ISE for authentication, authorization, and accounting (AAA) in network access devices (NAD), this vulnerability is of particular concern. Any organization utilizing Cisco ISE in their infrastructure should be aware of this vulnerability and take immediate steps to mitigate the risk of exploitation.
Vulnerability Summary
CVE ID: CVE-2025-20152
Severity: High (8.6 CVSS Severity Score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Possible system compromise or data leakage
Affected Products
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Product | Affected Versions
Cisco Identity Services Engine (ISE) | All versions prior to the latest patch
How the Exploit Works
This vulnerability stems from improper handling of certain RADIUS requests within the Cisco ISE. An attacker can exploit this vulnerability by sending a specific authentication request to a network access device (NAD) that uses Cisco ISE for AAA. A successful exploit could cause the Cisco ISE to reload, leading to a denial of service condition. This could potentially provide the attacker with an opportunity to compromise the system or leak data.
Conceptual Example Code
Here is a conceptual example of a potential malicious RADIUS request that could exploit this vulnerability. Note that this is a simplified representation and actual exploitation would likely involve more complex techniques.
POST /radius/authentication HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "auth_request": "malicious_payload" }In the above example, “malicious_payload” represents a specially crafted authentication request designed to trigger the vulnerability in Cisco ISE’s RADIUS message processing feature.
Recommendations for Mitigation
Organizations are advised to apply the patch provided by Cisco to remediate this vulnerability. In situations where immediate patching is not possible, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as temporary mitigation. Regularly updating and patching systems, following a least privilege model, and monitoring network traffic can also help prevent the exploitation of such vulnerabilities.