CVE-2019-16227
📋 TL;DR
CVE-2019-16227 is a critical memory corruption vulnerability in py-lmdb 0.97 that allows attackers to trigger an invalid write operation via memcpy when processing malicious data.mdb files. This can lead to arbitrary code execution or denial of service. Any application using the vulnerable py-lmdb library to process untrusted LMDB database files is affected.
💻 Affected Systems
- py-lmdb
📦 What is this software?
Py Lmdb by Py Lmdb Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with the privileges of the application processing the malicious database file, potentially leading to complete system compromise.
Likely Case
Application crash (denial of service) or memory corruption leading to unpredictable behavior.
If Mitigated
Limited impact if the application runs with minimal privileges and processes only trusted database files.
🎯 Exploit Status
Proof-of-concept code is publicly available. Exploitation requires the attacker to supply a malicious data.mdb file to the vulnerable application.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: py-lmdb 0.98 and later
Vendor Advisory: https://github.com/jnwatson/py-lmdb/issues/167
Restart Required: Yes
Instructions:
1. Upgrade py-lmdb to version 0.98 or later using pip: 'pip install --upgrade lmdb'. 2. Restart any applications using py-lmdb to load the patched library.
🔧 Temporary Workarounds
Input validation for LMDB files
allImplement strict validation to ensure only trusted, known-good data.mdb files are processed by the application.
Sandboxing
allRun the application in a sandboxed environment with limited privileges to reduce impact if exploitation occurs.
🧯 If You Can't Patch
- Restrict file uploads or processing of external LMDB files to trusted sources only.
- Implement application-level monitoring for crashes or abnormal behavior related to database file processing.
🔍 How to Verify
Check if Vulnerable:
Check the installed py-lmdb version: 'pip show lmdb' or 'python -c "import lmdb; print(lmdb.__version__)"'. If version is 0.97, the system is vulnerable.Check Version:
python -c "import lmdb; print(lmdb.__version__)"Verify Fix Applied:
After upgrading, verify the version is 0.98 or higher using the same commands.📡 Detection & Monitoring
Log Indicators:
- Application crashes or segmentation faults when processing database files
- Unexpected memory access errors in application logs
Network Indicators:
- Unusual file uploads of .mdb files to vulnerable endpoints
SIEM Query:
Example: 'event_type:crash AND process_name:*python* AND error_message:*memcpy* OR *segmentation fault*'