CVE-2024-20296: Cisco Identity Services Engine RCE Flaw

CVE-2024-20296 Overview

A vulnerability exists in the web-based management interface of Cisco Identity Services Engine (ISE) that could allow an authenticated, remote attacker to upload arbitrary files to an affected device. This vulnerability stems from improper validation of files uploaded through the web-based management interface, enabling attackers with valid Policy Admin credentials to store malicious files, execute arbitrary commands on the underlying operating system, and escalate privileges to root.

Critical Impact
Authenticated attackers can leverage this arbitrary file upload vulnerability to achieve remote code execution with root privileges on Cisco ISE deployments, potentially compromising the entire network access control infrastructure.

Affected Products

Cisco Identity Services Engine 3.1.0 (including patches 1-9)
Cisco Identity Services Engine 3.2.0 (including patches 1-6)
Cisco Identity Services Engine 3.3.0 (including patches 1-2)

Discovery Timeline

July 17, 2024 - CVE-2024-20296 published to NVD
April 7, 2025 - Last updated in NVD database

Technical Details for CVE-2024-20296

Vulnerability Analysis

This vulnerability (CWE-434: Unrestricted Upload of File with Dangerous Type) affects the web-based management interface of Cisco Identity Services Engine. The flaw allows authenticated attackers with Policy Admin credentials to bypass file upload restrictions and place malicious content on the system.

The attack requires network access to the ISE management interface and high-privilege credentials (Policy Admin role), but once these prerequisites are met, exploitation does not require user interaction. A successful attack can result in complete compromise of the confidentiality, integrity, and availability of the affected system.

The vulnerability is particularly dangerous because Cisco ISE serves as a critical network access control platform. Compromising ISE could allow attackers to manipulate network authentication policies, gain access to sensitive authentication data, and potentially pivot to other network resources.

Root Cause

The root cause of CVE-2024-20296 is improper validation of files uploaded through the web-based management interface. The ISE application fails to adequately verify the content type, file extension, or dangerous file signatures during the upload process. This allows attackers to upload executable files, scripts, or other malicious content that would normally be blocked by proper file validation controls.

Attack Vector

The attack vector for this vulnerability is network-based, targeting the web-based management interface of Cisco ISE. An attacker must first obtain valid Policy Admin credentials through credential theft, social engineering, or other means. Once authenticated, the attacker can:

Access the file upload functionality within the ISE management interface
Craft a malicious file designed to execute commands on the underlying system
Upload the malicious file, bypassing insufficient validation controls
Trigger execution of the uploaded file to gain command execution
Escalate privileges to root level on the affected ISE appliance

The attack does not require any user interaction beyond the attacker's own actions, making it reliable once the prerequisite credentials are obtained.

Detection Methods for CVE-2024-20296

Indicators of Compromise

Unexpected files appearing in upload directories on Cisco ISE systems
Unauthorized processes running with elevated privileges on ISE appliances
Anomalous network connections originating from ISE management interfaces
Evidence of privilege escalation attempts in system logs

Detection Strategies

Monitor Cisco ISE admin audit logs for unusual file upload activity from Policy Admin accounts
Implement file integrity monitoring on ISE systems to detect unauthorized file modifications
Review authentication logs for suspicious Policy Admin credential usage patterns
Deploy network traffic analysis to identify unusual outbound connections from ISE management interfaces

Monitoring Recommendations

Enable comprehensive logging on all Cisco ISE management interface activities
Configure alerts for multiple file uploads from single admin sessions
Monitor for process creation events on ISE systems, particularly those spawning shell processes
Implement behavioral analysis for Policy Admin accounts to detect credential compromise

How to Mitigate CVE-2024-20296

Immediate Actions Required

Review and audit all Policy Admin accounts and remove unnecessary privileges
Implement network segmentation to restrict access to ISE management interfaces
Enable multi-factor authentication for all administrative access to ISE
Monitor ISE systems for signs of compromise while awaiting patch deployment

Patch Information

Cisco has released a security advisory addressing this vulnerability. Administrators should consult the Cisco Security Advisory for specific patch information and upgrade guidance for their affected ISE versions.

Organizations running Cisco ISE versions 3.1.0 through patch 9, 3.2.0 through patch 6, or 3.3.0 through patch 2 should prioritize patching as this vulnerability enables privilege escalation to root.

Workarounds

Restrict network access to the ISE management interface to trusted administrator workstations only
Implement strict access control lists (ACLs) limiting which IP addresses can reach the management interface
Review and minimize the number of accounts with Policy Admin privileges
Deploy web application firewalls or reverse proxies with file upload inspection capabilities in front of ISE management interfaces

bash

# Example: Restrict ISE management interface access via firewall
# Allow only trusted administrator subnet to reach ISE management port
iptables -A INPUT -p tcp --dport 443 -s 10.10.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP