CVE-2023-39584
📋 TL;DR
CVE-2023-39584 is an arbitrary file read vulnerability in Hexo static site generator that allows attackers to read sensitive files from the server filesystem. This affects all Hexo installations up to version 7.0.0 (RC2) that use the include_code tag plugin. Site administrators and developers using vulnerable Hexo versions are at risk.
💻 Affected Systems
- Hexo
📦 What is this software?
Hexo by Hexo
Hexo by Hexo
Hexo by Hexo
⚠️ Risk & Real-World Impact
Worst Case
Attackers could read sensitive server files including configuration files, environment variables, SSH keys, database credentials, and other confidential data, potentially leading to complete system compromise.
Likely Case
Attackers read configuration files containing API keys, database credentials, or other sensitive information that could be used for further attacks or data theft.
If Mitigated
With proper file permissions and network segmentation, impact is limited to files accessible by the Hexo process user account.
🎯 Exploit Status
Exploitation requires the attacker to be able to submit content that gets processed by Hexo's include_code tag, typically through blog posts or content submission.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.0.0 (stable release) and later
Vendor Advisory: https://github.com/hexojs/hexo/issues/5250
Restart Required: Yes
Instructions:
1. Update Hexo to version 7.0.0 or later using npm: npm update hexo@latest
2. Restart the Hexo server or rebuild the static site
3. Verify the update with: hexo version
🔧 Temporary Workarounds
Disable include_code plugin
allRemove or disable the vulnerable include_code tag plugin to prevent exploitation
Remove or comment out the include_code plugin configuration in _config.yml
Restrict file access permissions
linuxSet strict file permissions to limit what files Hexo process can read
chmod 600 sensitive_files
chown root:root sensitive_files
🧯 If You Can't Patch
- Disable the include_code tag plugin entirely
- Implement strict input validation and sanitization for all user-submitted content
🔍 How to Verify
Check if Vulnerable:
Check Hexo version with: hexo version. If version is 7.0.0-rc2 or earlier, the system is vulnerable.Check Version:
hexo versionVerify Fix Applied:
Verify Hexo version is 7.0.0 or later with: hexo version📡 Detection & Monitoring
Log Indicators:
- Unusual file read attempts in server logs
- Multiple include_code tag usage with suspicious file paths
- Error logs showing file not found for unusual paths
Network Indicators:
- Unusual HTTP requests to Hexo endpoints with include_code parameters
- Requests containing path traversal patterns
SIEM Query:
source="hexo.log" AND ("include_code" OR ".." OR "/etc/" OR "/root/")🔗 References
- https://github.com/hexojs/hexo/blob/a3e68e7576d279db22bd7481914286104e867834/lib/plugins/tag/include_code.js#L49
- https://github.com/hexojs/hexo/issues/5250
- https://www.gem-love.com/2023/07/25/hexo%E5%8D%9A%E5%AE%A2%E4%BB%BB%E6%84%8F%E6%96%87%E4%BB%B6%E8%AF%BB%E5%8F%96%E5%92%8C%E4%BB%A3%E7%A0%81%E6%89%A7%E8%A1%8C%E6%BC%8F%E6%B4%9E/#undefined
- https://github.com/hexojs/hexo/blob/a3e68e7576d279db22bd7481914286104e867834/lib/plugins/tag/include_code.js#L49
- https://github.com/hexojs/hexo/issues/5250
- https://www.gem-love.com/2023/07/25/hexo%E5%8D%9A%E5%AE%A2%E4%BB%BB%E6%84%8F%E6%96%87%E4%BB%B6%E8%AF%BB%E5%8F%96%E5%92%8C%E4%BB%A3%E7%A0%81%E6%89%A7%E8%A1%8C%E6%BC%8F%E6%B4%9E/#undefined
