CVE-2025-20281: Cisco Identity Services Engine RCE Flaw

CVE-2025-20281 Overview

A vulnerability in a specific API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to execute arbitrary code on the underlying operating system as root. The attacker does not require any valid credentials to exploit this vulnerability.

Critical Impact
This vulnerability may allow an unauthenticated attacker to gain root privileges, posing a severe risk to network infrastructure.

Affected Products

Cisco Identity Services Engine
Cisco Identity Services Engine Passive Identity Connector

Discovery Timeline

Not Available - Vulnerability discovered by Unknown
Not Available - Responsible disclosure to Cisco
Not Available - CVE CVE-2025-20281 assigned
Not Available - Cisco releases security patch
2025-06-25 - CVE CVE-2025-20281 published to NVD
2025-10-28 - Last updated in NVD database

Technical Details for CVE-2025-20281

Vulnerability Analysis

This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by submitting a crafted API request.

Root Cause

The root cause of this issue lies in improper input validation within the API, allowing crafted inputs to be processed and executed.

Attack Vector

The attack vector for this vulnerability is over the network, where a remote attacker can send crafted API requests to the affected system.

python

# Example exploitation code (sanitized)
import requests

url = "http://vulnerable-cisco-device/api/vulnerable-endpoint"
payload = { 'malicious_input': 'crafted_data' }

response = requests.post(url, json=payload)
print(response.text)

Detection Methods for CVE-2025-20281

Indicators of Compromise

Unusual outbound network traffic
Sudden increase in privilege-level processes
Modified system files or configurations

Detection Strategies

Network monitoring systems should be configured to detect anomalous API requests. Logging should be enabled for all API activities.

Monitoring Recommendations

Utilize intrusion detection systems (IDS) to flag unusual API request patterns. Regularly review logs for unauthorized access attempts.

How to Mitigate CVE-2025-20281

Immediate Actions Required

Disable affected API endpoints if possible
Monitor network traffic for signs of exploitation
Enforce strict input validation on user-supplied data

Patch Information

Cisco has released patches as part of their security advisories. Users are advised to upgrade to the latest version as outlined in the vendor's advisory.

Workarounds

As a temporary measure, access to vulnerable endpoints can be restricted through network segmentation and firewall rules until patches can be applied.

bash

# Configuration example
echo "Blocking vulnerable API access"
iptables -A INPUT -p tcp --dport 80 -s <source_ip> -j DROP