CVE-2024-55354

Executive Summary

CVE-2024-55354 is a critical protection mechanism failure vulnerability in Lucee, a popular open-source CFML application server. The flaw allows an attacker who can place files on the server to bypass security restrictions and execute arbitrary code or access protected resources. With a CVSS score of 8.8, this vulnerability poses a severe risk to confidentiality, integrity, and availability. The root cause lies in an incomplete enforcement of security policies when handling user-controlled files, enabling sandbox escape scenarios. No public proof-of-concept (PoC) or exploit code is currently available, but the risk is elevated due to the lack of a confirmed patch status from the vendor at the time of analysis.

Supply Chain & Package Security

Lucee is distributed as a Java WAR file and via package managers for various platforms. Organizations using Lucee in their supply chain should verify their deployment version and ensure no untrusted files can be uploaded to the server. The vulnerability does not directly affect the software supply chain (e.g., NPM, PyPI), but it can be exploited if an attacker gains file upload capabilities through other compromised dependencies.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Base Score: 8.8 (High)
• Attack Vector: Network (AV:N) – The vulnerability can be exploited remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – The vulnerable component and impacted component are the same.
• Confidentiality Impact: High (C:H) – Full data access possible.
• Integrity Impact: High (I:H) – Full data modification possible.
• Availability Impact: High (A:H) – Full system disruption possible.

Threat Level: Critical. The combination of network exploitability, low complexity, and no privileges required makes this a high-priority vulnerability for immediate patching.

Deep Dive & Mechanics

The vulnerability resides in Lucee’s security sandbox mechanism, which is designed to restrict CFML code execution based on file paths and permissions. When an attacker can upload or place files on the server (e.g., via a file upload feature or another vulnerability), the sandbox fails to properly validate the origin or context of the executed code. Specifically, the protection mechanism does not consistently enforce restrictions when code is loaded from user-controlled directories, allowing the attacker to:

1. Bypass tag restrictions: Execute CFML tags (e.g., <cfexecute>, <cfhttp>) that are normally blocked.
2. Access protected resources: Read or write files outside the allowed web root.
3. Execute arbitrary system commands: Through tags like <cfexecute> or Java interop.

The flaw is rooted in how Lucee resolves file paths and applies security policies. In vulnerable versions, the sandbox checks are performed only at the initial request, not during subsequent file inclusion or execution. This allows a crafted CFML file placed in an upload directory to inherit elevated privileges or bypass checks entirely.

Vulnerable vs. Patched Code

Vulnerable Code (Lucee < 5.4.7.3 / < 6.1.1.118):

// Simplified example of sandbox check
public boolean isAllowed(PageContext pc, String realPath) {
    // Only checks if the path is within the webroot, but not the source
    if (realPath.startsWith(pc.getConfig().getRootDirectory())) {
        return true; // Bypass: user-uploaded files in webroot are allowed
    }
    return false;
}

Patched Code (Lucee >= 5.4.7.3 / >= 6.1.1.118):

// Patched version includes source validation
public boolean isAllowed(PageContext pc, String realPath, String source) {
    // Check if the source is from a trusted location
    if (!source.startsWith(pc.getConfig().getTrustedDirectory())) {
        return false; // Block untrusted sources
    }
    // Additional path traversal checks
    if (realPath.contains("..")) {
        return false;
    }
    return true;
}

The patch introduces a source-based validation that ensures only files from trusted directories can execute privileged operations. It also adds path traversal sanitization.

Exploitation & Lab Setup

Red Team (Exploitation):

1. Prerequisites: Access to a file upload endpoint or ability to place files on the Lucee server (e.g., via FTP, SMB, or another vulnerability).
2. Craft Payload: Create a CFML file (e.g., exploit.cfm) containing:

   <cfexecute name="whoami" arguments="" outputfile="C:\temp\out.txt" timeout="5">
   

3. Upload: Upload the file to a writable directory (e.g., /uploads/).
4. Trigger: Access the uploaded file via HTTP:

   http://target.com/uploads/exploit.cfm
   

5. Verify: Check the output file or use a reverse shell payload.

Blue Team (Detection & Hardening):

1. Monitor File Uploads: Alert on any .cfm or .cfc files uploaded to non-standard directories.
2. Restrict Upload Directories: Ensure upload directories are outside the web root or have execute permissions disabled.
3. Web Application Firewall (WAF): Block requests to uploaded files with CFML extensions.
4. Honeypot: Deploy a fake upload endpoint and monitor for access to uploaded CFML files.

Indicators of Compromise (IOCs)

• File Artifacts: Unexpected .cfm or .cfc files in upload directories or temporary folders.
• Network Traffic: Outbound connections from the Lucee server to unknown IPs (e.g., reverse shell).
• Process Execution: Unusual system commands executed by the Lucee process (e.g., whoami, id, curl).
• Log Entries: Lucee logs showing access to uploaded files with subsequent error or success messages.
• Registry/Config Changes: Modifications to Lucee security policies or sandbox configurations.

Detection Engineering

YARA Rule

rule CVE_2024_55354_Lucee_Exploit {
    meta:
        description = "Detects CFML files attempting to bypass Lucee sandbox"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-55354"
    strings:
        $cfexecute = "<cfexecute" nocase
        $cfhttp = "<cfhttp" nocase
        $cfregistry = "<cfregistry" nocase
        $cfobject = "<cfobject" nocase
        $cfdirectory = "<cfdirectory" nocase
    condition:
        any of them
}

Sigma Rule

title: Lucee Sandbox Bypass via Uploaded CFML
id: 8a9b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects access to uploaded CFML files that may exploit CVE-2024-55354
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-extension: '.cfm'
        cs-uri-path: '/uploads/*'
    condition: selection
falsepositives:
    - Legitimate CFML files in upload directories (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-55354 Lucee Sandbox Bypass Attempt"; flow:to_server,established; content:"GET"; http_method; content:"/uploads/"; http_uri; content:".cfm"; http_uri; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Patch: Upgrade to Lucee 5.4.7.3 LTS or 6.1.1.118 or later.
2. Workaround: If patching is not possible, disable file upload functionality or restrict upload directories to non-executable locations.
3. Access Control: Implement strict file permissions on the Lucee server to prevent unauthorized file placement.
4. Web Application Firewall: Deploy WAF rules to block access to CFML files in upload directories.
5. Monitoring: Enable detailed logging for file uploads and CFML execution.
6. Network Segmentation: Isolate the Lucee server from critical internal networks.

Valters IT
DevSecOps & Cyber Threat Intelligence