CVE-2025-20125: Cisco ISE Authorization Bypass Flaw

CVE-2025-20125 Overview

A vulnerability in an API of Cisco ISE could allow an authenticated, remote attacker with valid read-only credentials to obtain sensitive information, change node configurations, and restart the node.

This vulnerability is due to a lack of authorization in a specific API and improper validation of user-supplied data. An attacker could exploit this vulnerability by sending a crafted HTTP request to a specific API on the device. A successful exploit could allow the attacker to obtain information, modify system configuration, and reload the device.

Critical Impact
Allows unauthorized changes to node configuration and denial of service through restart.

Affected Products

Cisco Identity Services Engine 3.1.0 (all patches up to 9)
Cisco Identity Services Engine 3.2.0 (patches 1 to 6)
Cisco Identity Services Engine 3.3.0 (patches 1 to 3)

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to Cisco
Not Available - CVE CVE-2025-20125 assigned
Not Available - Cisco releases security patch
2025-02-05 - CVE CVE-2025-20125 published to NVD
2025-03-28 - Last updated in NVD database

Technical Details for CVE-2025-20125

Vulnerability Analysis

This vulnerability arises from insufficient authorization in the API handling login requests. The service fails to enforce adequate permission checks, allowing attackers possessing read-only credentials to perform unauthorized actions including sensitive data extraction and configuration changes.

Root Cause

Improper authorization checks and lack of proper validation for user-supplied inputs in API requests.

Attack Vector

An attacker can exploit this vulnerability by sending specifically crafted HTTP requests to the API, leveraging valid read-only credentials.

http

POST /api/endpoint HTTP/1.1
Host: target_host
Authorization: Basic cmVhZG9ubHk6cGFzc3dvcmQ=
Content-Type: application/json

{
  "action": "CHANGE_CONFIG",
  "parameters": {}
}

Detection Methods for CVE-2025-20125

Indicators of Compromise

Unusual configuration changes logged
Unexpected node restarts
Excessive API requests from read-only accounts

Detection Strategies

Use anomaly detection tools to monitor API accesses and flag unauthorized operations originating from accounts with limited privileges. Implement comprehensive logging of API requests and changes to configurations.

Monitoring Recommendations

Continuously monitor API logs for unusual patterns or frequency spikes in requests from known read-only accounts, especially those performing non-standard actions.

How to Mitigate CVE-2025-20125

Immediate Actions Required

Revoke unnecessary API access for read-only accounts
Implement additional authorization checks in API
Patch affected systems as soon as updates are available

Patch Information

Refer to the official Cisco advisory for patch details and apply them promptly: Cisco Security Advisory

Workarounds

Restrict API access by IP address and ensure strict network segmentation.

bash

# Example to restrict access using firewall
iptables -A INPUT -p tcp --dport 443 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP