CVE-2021-44496
📋 TL;DR
This vulnerability in FIS GT.M (and related YottaDB) allows attackers to execute arbitrary code by exploiting a buffer overflow in memcpy. Attackers can control size variables and buffers through crafted input, potentially gaining full system control. Systems running affected GT.M/YottaDB versions are vulnerable.
💻 Affected Systems
- FIS GT.M
- YottaDB
📦 What is this software?
Gt.m by Fisglobal
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise leading to data theft, ransomware deployment, or persistent backdoor installation
Likely Case
Remote code execution allowing attacker to run arbitrary commands with application privileges
If Mitigated
Limited impact if proper network segmentation and least privilege are enforced
🎯 Exploit Status
Requires crafting specific input to trigger buffer overflow, but no authentication needed
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V7.0-002 and later
Vendor Advisory: http://tinco.pair.com/bhaskar/gtm/doc/articles/GTM_V7.0-002_Release_Notes.html
Restart Required: Yes
Instructions:
1. Download GT.M V7.0-002 or later from sourceforge.net/projects/fis-gtm/files/ 2. Stop all GT.M/YottaDB processes 3. Install the updated version 4. Restart services
🔧 Temporary Workarounds
Input validation and sanitization
allImplement strict input validation for all data passed to GT.M/YottaDB functions
Network isolation
linuxRestrict network access to GT.M/YottaDB services to trusted sources only
iptables -A INPUT -p tcp --dport [gtm_port] -s [trusted_ip] -j ACCEPT
iptables -A INPUT -p tcp --dport [gtm_port] -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to isolate GT.M/YottaDB systems
- Deploy application-level firewalls to monitor and block suspicious input patterns
🔍 How to Verify
Check if Vulnerable:
Check GT.M version with: $gtm_dist/mumps -version | grep 'GT.M'Check Version:
$gtm_dist/mumps -version | grep 'GT.M'Verify Fix Applied:
Verify version is V7.0-002 or later using same command📡 Detection & Monitoring
Log Indicators:
- Unusual process crashes of GT.M/YottaDB
- Abnormal memory usage patterns
- Suspicious input patterns in application logs
Network Indicators:
- Unexpected connections to GT.M ports
- Large or malformed network packets to GT.M services
SIEM Query:
process_name:"mumps" AND (event_type:"crash" OR memory_usage:>threshold)🔗 References
- http://tinco.pair.com/bhaskar/gtm/doc/articles/GTM_V7.0-002_Release_Notes.html
- https://gitlab.com/YottaDB/DB/YDB/-/issues/828
- https://sourceforge.net/projects/fis-gtm/files/
- http://tinco.pair.com/bhaskar/gtm/doc/articles/GTM_V7.0-002_Release_Notes.html
- https://gitlab.com/YottaDB/DB/YDB/-/issues/828
- https://sourceforge.net/projects/fis-gtm/files/
