CVE-2023-24698
📋 TL;DR
This vulnerability allows attackers to perform directory traversal attacks by exploiting insufficient parameter validation in Foswiki's Sandbox component. Attackers can access files outside the intended directory via crafted web requests. Affects Foswiki installations version 2.1.7 and below.
💻 Affected Systems
- Foswiki
📦 What is this software?
Foswiki by Foswiki
⚠️ Risk & Real-World Impact
Worst Case
Attackers could read sensitive system files, potentially leading to information disclosure, privilege escalation, or remote code execution if combined with other vulnerabilities.
Likely Case
Unauthorized access to arbitrary files on the server, compromising confidential data such as configuration files or user information.
If Mitigated
Limited impact if proper input validation and access controls are enforced, restricting file access to authorized directories only.
🎯 Exploit Status
Exploitation involves sending crafted web requests, which is straightforward, but no public proof-of-concept has been confirmed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Foswiki v2.1.8 or later
Vendor Advisory: https://foswiki.org/Support/SecurityAlert-CVE-2023-24698
Restart Required: Yes
Instructions:
1. Backup your Foswiki installation. 2. Upgrade to Foswiki v2.1.8 or later from the official website. 3. Restart the web server to apply changes. 4. Verify the fix by checking the version and testing for directory traversal.
🔧 Temporary Workarounds
Input Validation Enhancement
allImplement strict input validation to block directory traversal patterns in web requests.
Modify Foswiki configuration to sanitize user inputs; specific commands depend on server setup.
Web Application Firewall (WAF) Rules
allDeploy WAF rules to detect and block directory traversal attempts.
Add WAF rules targeting patterns like '../' or encoded equivalents in request parameters.
🧯 If You Can't Patch
- Restrict network access to Foswiki instances using firewalls to limit exposure to trusted IPs only.
- Monitor logs for suspicious file access patterns and implement intrusion detection systems.
🔍 How to Verify
Check if Vulnerable:
Check the Foswiki version; if it is v2.1.7 or below, it is vulnerable. Use version check command.Check Version:
Check the Foswiki version in the admin interface or via command: grep -r 'VERSION' /path/to/foswiki/lib/Foswiki.pmVerify Fix Applied:
After patching, confirm the version is v2.1.8 or later and test with directory traversal attempts to ensure they are blocked.📡 Detection & Monitoring
Log Indicators:
- Log entries showing access to files with '../' patterns or unusual file paths in web requests.
Network Indicators:
- HTTP requests containing directory traversal sequences like '../' or URL-encoded equivalents.
SIEM Query:
Example: search 'web_access_logs' where uri contains '../' or '%2e%2e%2f'