CVE-2025-52566
📋 TL;DR
A signed vs. unsigned integer overflow vulnerability in llama.cpp's tokenizer allows heap overflow when processing manipulated text input during tokenization. This affects all llama.cpp users running versions prior to b5721. Attackers could potentially execute arbitrary code or crash the inference engine.
💻 Affected Systems
- llama.cpp
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data exfiltration, or lateral movement within the environment.
Likely Case
Application crash (denial of service) or memory corruption leading to unstable behavior during text processing.
If Mitigated
Limited impact with proper input validation and memory protection mechanisms in place.
🎯 Exploit Status
Exploitation requires crafting specific text input to trigger the integer overflow during tokenization.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: b5721 and later
Vendor Advisory: https://github.com/ggml-org/llama.cpp/security/advisories/GHSA-7rxv-5jhh-j6xx
Restart Required: Yes
Instructions:
1. Check current llama.cpp version
2. Update to version b5721 or later: git pull origin master
3. Rebuild: make clean && make
4. Restart any running llama.cpp processes
🔧 Temporary Workarounds
Input validation and sanitization
allImplement strict input validation to reject suspicious or malformed text inputs before tokenization
Memory protection hardening
linuxEnable ASLR, DEP, and other memory protection mechanisms at OS level
sysctl -w kernel.randomize_va_space=2
🧯 If You Can't Patch
- Isolate llama.cpp instances in restricted containers or VMs with minimal privileges
- Implement network segmentation to limit access to vulnerable instances
🔍 How to Verify
Check if Vulnerable:
Check llama.cpp version: ./main --version or examine source code for commit hash prior to dd6e6d0b6a4bbe3ebfc931d1eb14db2f2b1d70afCheck Version:
./main --version 2>&1 | grep -i version || git log --oneline -1Verify Fix Applied:
Verify version is b5721 or later and commit includes dd6e6d0b6a4bbe3ebfc931d1eb14db2f2b1d70af📡 Detection & Monitoring
Log Indicators:
- Segmentation faults in llama.cpp processes
- Unexpected process termination during text processing
- Memory allocation errors in system logs
Network Indicators:
- Unusual patterns of text input to llama.cpp endpoints
- Repeated connection attempts followed by service crashes
SIEM Query:
process_name:"llama" AND (event_type:"crash" OR event_type:"segfault")