CVE-2023-26347: Adobe ColdFusion Auth Bypass Vulnerability

CVE-2023-26347 Overview

CVE-2023-26347 is an Improper Access Control vulnerability affecting Adobe ColdFusion versions 2023.5 (and earlier) and 2021.11 (and earlier). This security flaw allows an unauthenticated attacker to bypass security features and gain unauthorized access to administration CFM and CFC endpoints. The vulnerability can be exploited remotely over the network without requiring any user interaction, making it particularly dangerous for internet-facing ColdFusion deployments.

Critical Impact

Unauthenticated attackers can bypass access controls to reach administrative endpoints, potentially exposing sensitive configuration data, server information, and enabling further exploitation of the ColdFusion server.

Affected Products

• Adobe ColdFusion 2023 (Update 5 and earlier)
• Adobe ColdFusion 2021 (Update 11 and earlier)
• All prior updates of Adobe ColdFusion 2023 and 2021 release lines

Discovery Timeline

• 2023-11-17 - CVE-2023-26347 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-26347

Vulnerability Analysis

This vulnerability falls under CWE-284 (Improper Access Control), indicating a fundamental flaw in how Adobe ColdFusion validates and enforces access restrictions to sensitive administrative endpoints. The access control mechanism fails to properly authenticate requests to CFM (ColdFusion Markup) and CFC (ColdFusion Component) endpoints that should be restricted to authorized administrators only.

The vulnerability is particularly concerning because it enables unauthenticated network-based attackers to reach administration interfaces that are designed to manage critical server configurations. Successful exploitation could lead to disclosure of sensitive configuration information, database connection strings, and other protected data accessible through administrative interfaces.

Root Cause

The root cause of CVE-2023-26347 lies in improper validation of access control rules within Adobe ColdFusion's request handling mechanism. The application fails to enforce proper authentication checks before granting access to administrative CFM and CFC endpoints. This creates a security bypass condition where attackers can craft requests that circumvent the intended access restrictions.

Attack Vector

The attack vector is network-based, requiring no authentication and no user interaction. An attacker can exploit this vulnerability by sending specially crafted HTTP requests directly to vulnerable ColdFusion administration endpoints. The attack can be executed from anywhere on the network that has connectivity to the ColdFusion server.

The exploitation flow involves identifying exposed ColdFusion servers, crafting requests to administrative CFM and CFC endpoints, and bypassing the access control mechanisms to gain unauthorized access. This could allow attackers to enumerate server configurations, access sensitive data, or potentially chain this vulnerability with other exploits for deeper compromise.

Detection Methods for CVE-2023-26347

Indicators of Compromise

• Unexpected HTTP requests to ColdFusion administration directories such as /CFIDE/administrator/ or /CFIDE/adminapi/
• Access attempts to CFM and CFC files within administrative paths from unauthenticated sources
• Anomalous access patterns to ColdFusion component endpoints from external IP addresses
• Log entries showing successful access to administrative endpoints without corresponding authentication events

Detection Strategies

• Monitor web server access logs for requests targeting /CFIDE/ administrative paths from unauthorized sources
• Implement web application firewall (WAF) rules to detect and block attempts to access administrative ColdFusion endpoints
• Configure intrusion detection systems (IDS) to alert on patterns consistent with ColdFusion administration endpoint enumeration
• Review ColdFusion server logs for authentication bypass attempts and unauthorized administrative access

Monitoring Recommendations

• Enable detailed access logging on ColdFusion servers to capture all requests to administrative endpoints
• Set up real-time alerting for any access attempts to /CFIDE/administrator/ and /CFIDE/adminapi/ paths
• Implement network monitoring to detect scanning activity targeting ColdFusion servers
• Regularly audit access logs for signs of reconnaissance or exploitation attempts

How to Mitigate CVE-2023-26347

Immediate Actions Required

• Apply the latest security updates from Adobe for ColdFusion 2023 and 2021 immediately
• Restrict network access to ColdFusion administration endpoints using firewall rules
• Ensure the /CFIDE/administrator/ and /CFIDE/adminapi/ directories are not accessible from untrusted networks
• Review access logs for signs of prior exploitation attempts

Patch Information

Adobe has released security patches addressing this vulnerability in the Adobe ColdFusion Security Advisory (APSB23-52). Organizations should upgrade to ColdFusion 2023 Update 6 or later, and ColdFusion 2021 Update 12 or later to remediate this vulnerability. The patches implement proper access control validation for administrative endpoints.

Workarounds

• Block external access to /CFIDE/ directories at the web server or firewall level until patches can be applied
• Implement IP-based access restrictions to limit administrative endpoint access to trusted management networks only
• Use a reverse proxy with authentication to protect ColdFusion administrative interfaces
• Consider taking internet-facing ColdFusion servers offline until patching is complete if immediate patching is not possible

# Example Apache configuration to restrict CFIDE access
<Directory "/opt/coldfusion/cfusion/wwwroot/CFIDE">
    # Deny all access by default
    Require all denied
    
    # Allow only from trusted management network
    Require ip 10.0.0.0/8
    Require ip 192.168.1.0/24
</Directory>

# Block external access to administrator endpoints
<LocationMatch "^/CFIDE/(administrator|adminapi)">
    Require all denied
    Require ip 127.0.0.1
</LocationMatch>