CVE-2024-20466: Cisco ISE Information Disclosure Flaw

CVE-2024-20466 Overview

A vulnerability in the web-based management interface of Cisco Identity Services Engine (ISE) could allow an authenticated, remote attacker to obtain sensitive information from an affected device. This vulnerability is due to improper enforcement of administrative privilege levels for high-value sensitive data, allowing attackers with read-only Administrator privileges to access configuration data they should not be authorized to view.

Critical Impact

An attacker with read-only Administrator privileges can exploit this vulnerability to collect sensitive system configuration information, potentially exposing network access policies, identity credentials, and other critical infrastructure details.

Affected Products

• Cisco Identity Services Engine 3.1.0 (including patches 1-9)
• Cisco Identity Services Engine 3.2.0 (including patches 1-4)
• Cisco Identity Services Engine 3.3.0 (including patch 1)

Discovery Timeline

• 2024-08-21 - CVE-2024-20466 published to NVD
• 2025-03-31 - Last updated in NVD database

Technical Details for CVE-2024-20466

Vulnerability Analysis

This vulnerability represents a Broken Access Control flaw (CWE-266: Incorrect Privilege Assignment, CWE-863: Incorrect Authorization) in the Cisco ISE web-based management interface. The core issue lies in the failure to properly enforce privilege boundaries between different administrative roles. When a user with read-only Administrator privileges navigates to certain pages within the management interface, the application fails to validate whether that user is authorized to access the sensitive data displayed on those pages.

The vulnerability allows authenticated attackers to bypass the intended privilege separation model. While read-only administrators should only have visibility into non-sensitive operational data, this flaw enables them to access high-value configuration information that should be restricted to full administrators with elevated privileges.

Root Cause

The root cause of this vulnerability is improper enforcement of administrative privilege levels within the web-based management interface. The application does not adequately verify user authorization when rendering pages containing sensitive configuration data. This allows users with lower-privilege read-only Administrator accounts to access information that should only be visible to fully privileged administrators.

The authorization check appears to validate authentication (confirming the user is logged in) but fails to properly validate the user's specific privilege level before serving sensitive content. This represents a classic authorization bypass where authentication is confused with authorization.

Attack Vector

The attack vector is network-based and requires authentication. An attacker must first obtain valid credentials for a read-only Administrator account on the Cisco ISE web-based management interface. This could be achieved through:

1. Compromising legitimate read-only admin credentials via phishing, credential stuffing, or other methods
2. Being assigned a read-only admin account as an insider with malicious intent
3. Exploiting weak password policies on read-only admin accounts

Once authenticated, the attacker simply browses to pages containing sensitive data. The vulnerability does not require any special exploitation techniques—the sensitive information is directly exposed through normal web interface navigation to unauthorized users.

Detection Methods for CVE-2024-20466

Indicators of Compromise

• Unusual access patterns by read-only Administrator accounts accessing configuration pages they typically don't visit
• Read-only admin sessions accessing sensitive configuration endpoints or data export functions
• Increased browsing activity across administrative pages by accounts with limited privilege scope
• Access logs showing read-only admins viewing certificate, credential, or policy configuration pages

Detection Strategies

• Implement detailed access logging for all administrative interface requests, capturing both the user role and the pages accessed
• Create alerts for read-only Administrator accounts accessing pages typically restricted to full administrators
• Deploy user behavior analytics (UBA) to baseline normal read-only admin activity and detect anomalies
• Monitor authentication logs for unusual login patterns for read-only admin accounts

Monitoring Recommendations

• Enable comprehensive audit logging on Cisco ISE administrative interface access
• Review administrative access logs regularly for any read-only accounts accessing sensitive configuration pages
• Implement SIEM correlation rules to detect privilege boundary violations
• Configure real-time alerting for sensitive page access by low-privilege admin accounts

How to Mitigate CVE-2024-20466

Immediate Actions Required

• Review all read-only Administrator accounts and remove access for any accounts that are not strictly necessary
• Audit current read-only Administrator account usage to identify any potential prior exploitation
• Apply the latest security patches from Cisco for affected ISE versions
• Implement network segmentation to restrict administrative interface access to trusted management networks only

Patch Information

Cisco has released security updates to address this vulnerability. Organizations should update their Cisco Identity Services Engine installations to the latest patched versions. Consult the Cisco Security Advisory for specific version guidance and patch availability.

For ISE 3.1.0, 3.2.0, and 3.3.0 deployments, verify you are running the latest available patch level that addresses CVE-2024-20466.

Workarounds

• Restrict administrative interface access to only trusted networks via ACLs or firewall rules
• Review and minimize the number of read-only Administrator accounts
• Implement multi-factor authentication (MFA) for all administrative access
• Consider using Cisco ISE's built-in RBAC features to create more restrictive custom roles if full read-only admin access is not required
• Monitor for any suspicious browsing activity from read-only admin accounts until patching is complete

# Example: Restrict ISE admin interface access via ACL
# Apply to network devices protecting ISE management interface
access-list 101 permit tcp 10.10.10.0 0.0.0.255 host 192.168.1.100 eq 443
access-list 101 deny tcp any host 192.168.1.100 eq 443
access-list 101 permit ip any any