CVE-2025-20337: Cisco Identity Services Engine RCE Flaw

CVE-2025-20337 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. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by submitting a crafted API request. A successful exploit could allow the attacker to obtain root privileges on an affected device.

Critical Impact
This vulnerability allows remote code execution leading to unauthorized root access.

Affected Products

Cisco Identity Services Engine (ISE) 3.3.0 - 3.4.0
Cisco Identity Services Engine Passive Identity Connector (ISE-PIC) 3.3.0

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to Cisco
Not Available - CVE CVE-2025-20337 assigned
Not Available - Cisco releases security patch
2025-07-16T17:15:30.573 - CVE CVE-2025-20337 published to NVD
2025-10-28T13:58:55.447 - Last updated in NVD database

Technical Details for CVE-2025-20337

Vulnerability Analysis

The vulnerability arises from insufficient validation of input within a particular API of Cisco ISE and Cisco ISE-PIC, allowing attackers to execute arbitrary commands with root privileges. The vulnerability is classified under CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component).

Root Cause

The root cause is improper input validation, which fails to neutralize control characters and parameters that can be manipulated for code execution.

Attack Vector

The attack vector is network-based. An attacker can exploit this by sending specially crafted requests via the network to execute code remotely.

python

# Example exploitation code (sanitized)
import requests

url = "http://target-ip/api/vulnerable-endpoint"
headers = {
    "Content-Type": "application/json"
}
data = {
    "input": "crafted_payload"
}

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

Detection Methods for CVE-2025-20337

Indicators of Compromise

Unusual network connections from unknown IPs
Elevated privileges on the system without authorization
Unexpected API requests with abnormal parameters

Detection Strategies

Monitor for anomalous API traffic to endpoints handling user inputs and implement signatures to detect payload patterns known to exploit this vulnerability.

Monitoring Recommendations

Utilize network monitoring tools to capture and analyze traffic patterns. Anomalies in API request sizes or payload content should trigger alerts. SentinelOne's Behavioral AI can augment this by correlating events indicative of compromise.

How to Mitigate CVE-2025-20337

Immediate Actions Required

Isolate affected systems to prevent further exploitation
Monitor for repeated exploitation attempt patterns
Review network access logs for unauthorized ingress/egress traffic

Patch Information

Refer to Cisco's Advisory for details on available patches.

Workarounds

While applying patches is critical, interim network segmentation and strict input validation in API handlers can mitigate risk.

bash

# Configuration example for mitigations
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP