CVE-2023-26302
📋 TL;DR
This vulnerability allows attackers to cause denial of service in markdown-it-py's command line interface by providing invalid UTF-8 characters as input. It affects users of markdown-it-py versions before 2.2.0 who process untrusted user input through the CLI. The impact is limited to service disruption rather than data compromise.
💻 Affected Systems
- markdown-it-py
📦 What is this software?
Markdown It Py by Executablebooks
⚠️ Risk & Real-World Impact
Worst Case
Complete unavailability of markdown processing functionality through the CLI, potentially disrupting workflows that depend on markdown-it-py for content processing.
Likely Case
Temporary service interruption when processing malicious input, requiring manual intervention to restart the affected process.
If Mitigated
No impact if input validation or sanitization is implemented before passing data to markdown-it-py CLI.
🎯 Exploit Status
Exploitation requires ability to provide input to the CLI, which typically requires some level of access or control over input sources.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.2.0 and later
Vendor Advisory: https://github.com/executablebooks/markdown-it-py/commit/53ca3e9c2b9e9b295f6abf7f4ad2730a9b70f68c
Restart Required: No
Instructions:
1. Update markdown-it-py using pip: 'pip install --upgrade markdown-it-py>=2.2.0'
2. Verify the update with: 'pip show markdown-it-py'
3. Test markdown processing functionality
🔧 Temporary Workarounds
Input validation and sanitization
allValidate and sanitize all input before passing to markdown-it-py CLI to ensure only valid UTF-8 characters are processed
Use Python API instead of CLI
allUse markdown-it-py's Python API directly instead of the command line interface, as the vulnerability only affects the CLI
🧯 If You Can't Patch
- Implement strict input validation to reject invalid UTF-8 characters before processing
- Monitor and restrict access to the markdown-it-py CLI to trusted users/systems only
🔍 How to Verify
Check if Vulnerable:
Check markdown-it-py version with: 'python -c "import markdown_it; print(markdown_it.__version__)"' or 'pip show markdown-it-py'Check Version:
python -c "import markdown_it; print(markdown_it.__version__)"Verify Fix Applied:
Confirm version is 2.2.0 or higher using the version check command📡 Detection & Monitoring
Log Indicators:
- Process crashes or abnormal terminations of markdown-it-py CLI
- Error messages related to UTF-8 decoding failures
SIEM Query:
Process termination events for markdown-it-py with error codes or abnormal exit status