1. Introduction
BlueDragon Server / Server JX is vulnerable to multiple remote vulnerabilities, including cross-site scripting (XSS) and denial of service (DoS) attacks. This affects web servers running ColdFusion Markup Language (CFML) pages. An attacker could execute arbitrary code in a user’s browser or crash the server. Confidentiality, integrity, and availability may be impacted if exploited successfully.
2. Technical Explanation
- Root cause: Insufficient input validation on filenames used in error page generation.
- Exploit mechanism: An attacker sends a crafted request with a malicious filename, which is then reflected in the server’s response as part of an HTML error page. This can execute arbitrary JavaScript code in the user’s browser. The server also crashes when handling requests containing MS-DOS device names with ‘.cfm’.
- Scope: BlueDragon Server / Server JX versions 6.2.1 and earlier are affected.
3. Detection and Assessment
To confirm vulnerability, check the installed version of BlueDragon Server / Server JX. Thorough assessment involves attempting to trigger the XSS or DoS conditions.
- Quick checks: Check the product version via the web interface (if accessible) or by examining installation directories for version information.
- Scanning: Nessus vulnerability scanner can detect these vulnerabilities using plugin ID 30159. This is an example only, and other scanners may also provide detection capabilities.
- Logs and evidence: Examine server logs for error messages related to filename processing or unexpected crashes when handling ‘.cfm’ requests. Look for unusual characters in the log files.
# Example command placeholder:
# No specific command available, check version via UI or installation directory
4. Solution / Remediation Steps
Currently, there is no known solution available at this time for these vulnerabilities. The following steps outline a temporary mitigation strategy and preparation for future patching.
4.1 Preparation
- Services: No services need to be stopped, but monitor server resources closely during testing.
- Rollback plan: Restore from the pre-change backup if issues occur. Change window approval may be needed depending on your organization’s policies.
4.2 Implementation
- Step 1: Implement strict input validation and sanitization for all filenames processed by the server, especially those used in error page generation. This is a manual process requiring code changes.
- Step 2: Block requests containing MS-DOS device names with ‘.cfm’ extensions at the web server or firewall level.
4.3 Config or Code Example
Before
# Insecure code example (illustrative)
filename = request.getParameter("filename");
errorPageContent = "Error processing file: " + filename;
After
# Secure code example (illustrative)
filename = request.getParameter("filename");
// Sanitize the filename to remove potentially dangerous characters
sanitizedFilename = sanitizeFilename(filename);
errorPageContent = "Error processing file: " + sanitizedFilename;
function sanitizeFilename(filename) {
// Implement robust input validation and sanitization here
return filename.replace(/[^a-zA-Z0-9._-]/g, ""); // Example only - adjust as needed
}
4.4 Security Practices Relevant to This Vulnerability
Several security practices can help prevent this type of vulnerability.
- Least privilege: Run the BlueDragon Server / Server JX process with the minimum necessary privileges to limit the impact of a successful exploit.
- Safe defaults: Configure the server with secure default settings, minimizing unnecessary features or services that could introduce vulnerabilities.
4.5 Automation (Optional)
Automation is not directly applicable for this specific vulnerability without code changes. However, you can automate scanning and monitoring processes to detect exploitation attempts.
# Example Bash script for log monitoring:
#!/bin/bash
grep -i "error processing file" /path/to/blueDragon/logs | tee -a /var/log/blueDragon_errors.log
5. Verification / Validation
- Post-fix check: Verify that requests with malicious filenames are blocked or properly sanitized, preventing code execution in the browser.
- Re-test: Re-run the earlier detection methods (e.g., Nessus scan) to confirm the vulnerability is no longer detected.
- Monitoring: Monitor server logs for error messages related to filename processing or unexpected crashes, indicating potential exploitation attempts.
# Post-fix command and expected output (example)
# Attempt XSS payload via web interface - no code execution should occur.
6. Preventive Measures and Monitoring
Implement ongoing security measures to prevent similar vulnerabilities in the future.
- Baselines: Update your server baseline configuration to include strict input validation rules for all user-supplied data.
- Pipelines: Integrate static application security testing (SAST) tools into your CI/CD pipeline to identify potential XSS and other vulnerabilities during development.
- Asset and patch process: Establish a regular patch review cycle to promptly apply security updates for BlueDragon Server / Server JX and its dependencies.
7. Risks, Side Effects, and Roll Back
Implementing input validation may introduce compatibility issues with existing applications that rely on specific filename formats.
- Roll back: Restore the pre-change backup if compatibility issues or performance degradation occur. Revert any code changes made to implement input validation.
8. References and Resources
- Vendor advisory or bulletin: http://www.nessus.org/u?edca57c9
- NVD or CVE entry: CVE-2006-2310, CVE-2006-2311
- Product or platform documentation relevant to the fix: No specific documentation available at this time.