CVE-2021-37404
📋 TL;DR
CVE-2021-37404 is a critical heap buffer overflow vulnerability in Apache Hadoop's libhdfs native code that allows attackers to cause denial of service or execute arbitrary code by providing malicious file paths. This affects Hadoop deployments using the native HDFS client library. Organizations running vulnerable Hadoop versions are at risk.
💻 Affected Systems
- Apache Hadoop
📦 What is this software?
Hadoop by Apache
Hadoop by Apache
Hadoop by Apache
Hadoop by Apache
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with root/administrator privileges leading to complete system compromise, data exfiltration, and lateral movement within the Hadoop cluster.
Likely Case
Denial of service causing Hadoop services to crash, disrupting data processing pipelines and cluster operations.
If Mitigated
Limited impact if proper network segmentation and least privilege access controls prevent exploitation attempts.
🎯 Exploit Status
The vulnerability requires user-provided file paths, which could be supplied through various Hadoop interfaces or APIs.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apache Hadoop 2.10.2, 3.2.3, 3.3.2 or higher
Vendor Advisory: https://lists.apache.org/thread/2h56ztcj3ojc66qzf1nno88vjw9vd4wo
Restart Required: Yes
Instructions:
1. Download the patched version from Apache Hadoop website. 2. Backup current configuration and data. 3. Stop all Hadoop services. 4. Install the patched version. 5. Restore configuration. 6. Restart Hadoop services. 7. Verify functionality.
🔧 Temporary Workarounds
Disable native libhdfs
allConfigure Hadoop to use pure Java HDFS client instead of native libhdfs
Set hadoop.native.lib to false in core-site.xml
Restrict file path input
allImplement input validation and sanitization for all user-provided file paths
🧯 If You Can't Patch
- Implement strict network segmentation to isolate Hadoop clusters from untrusted networks
- Apply principle of least privilege and restrict user access to Hadoop services
🔍 How to Verify
Check if Vulnerable:
Check Hadoop version using 'hadoop version' command and compare against vulnerable versionsCheck Version:
hadoop versionVerify Fix Applied:
Verify version is 2.10.2+, 3.2.3+, or 3.3.2+ and test file operations with various path inputs📡 Detection & Monitoring
Log Indicators:
- Unusual file path patterns in Hadoop logs
- Hadoop service crashes or restarts
- Stack traces containing libhdfs or buffer overflow references
Network Indicators:
- Unusual connections to Hadoop services from unexpected sources
- Multiple failed file operations with malformed paths
SIEM Query:
source="hadoop.log" AND ("libhdfs" OR "buffer overflow" OR "segmentation fault")