CVE-2021-38592
📋 TL;DR
CVE-2021-38592 is a heap-based buffer overflow vulnerability in Wasm3 0.5.0's op_Const64 function that can be triggered during WebAssembly module loading. This allows attackers to execute arbitrary code or cause denial of service by providing malicious WebAssembly modules. Anyone using Wasm3 0.5.0 to execute untrusted WebAssembly code is affected.
💻 Affected Systems
- Wasm3
📦 What is this software?
Wasm3 by Wasm3 Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if the vulnerable process has sufficient privileges.
Likely Case
Denial of service through application crashes or memory corruption leading to instability.
If Mitigated
Limited impact if running with minimal privileges and proper sandboxing.
🎯 Exploit Status
Proof-of-concept available through OSS-Fuzz reports; exploitation requires providing malicious WebAssembly modules.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 0.5.0
Vendor Advisory: https://github.com/wasm3/wasm3/security/advisories
Restart Required: Yes
Instructions:
1. Update Wasm3 to version 0.5.1 or later. 2. Recompile any applications using Wasm3. 3. Restart affected services.
🔧 Temporary Workarounds
Disable untrusted WebAssembly execution
allPrevent loading of untrusted WebAssembly modules
Run with reduced privileges
linuxExecute Wasm3 with minimal system permissions
sudo -u nobody ./wasm3_app
🧯 If You Can't Patch
- Implement strict input validation for WebAssembly modules
- Deploy application sandboxing/containerization to limit blast radius
🔍 How to Verify
Check if Vulnerable:
Check if Wasm3 version is exactly 0.5.0Check Version:
wasm3 --versionVerify Fix Applied:
Verify Wasm3 version is 0.5.1 or later📡 Detection & Monitoring
Log Indicators:
- Segmentation faults
- Memory access violation errors
- Abnormal process termination
Network Indicators:
- Unexpected WebAssembly module uploads
- Suspicious module loading patterns
SIEM Query:
process.name:"wasm3" AND (event.action:"segmentation_fault" OR event.action:"memory_violation")