CVE-2024-27529
📋 TL;DR
CVE-2024-27529 is a memory leak vulnerability in wasm3's Read_utf8 function that allows attackers to cause denial of service through resource exhaustion. This affects applications using vulnerable versions of the wasm3 WebAssembly interpreter. Attackers can trigger repeated memory allocations that are never freed, gradually consuming system memory.
💻 Affected Systems
- wasm3
📦 What is this software?
Wasm3 by Wasm3 Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system memory exhaustion leading to denial of service, application crashes, and potential system instability affecting all services on the host.
Likely Case
Application crashes or degraded performance due to memory exhaustion, requiring restarts and causing service disruption.
If Mitigated
Limited impact with proper memory monitoring and restart policies, though still causing periodic service interruptions.
🎯 Exploit Status
Proof of concept available in GitHub issue. Exploitation requires ability to provide malicious WebAssembly modules to the interpreter.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after commit 139076a
Vendor Advisory: https://github.com/wasm3/wasm3/issues/462
Restart Required: Yes
Instructions:
1. Update wasm3 to latest version from GitHub repository. 2. Rebuild any applications using wasm3. 3. Restart affected services.
🔧 Temporary Workarounds
Input Validation
allImplement strict validation of WebAssembly module inputs before passing to wasm3 interpreter
Memory Limits
linuxConfigure memory limits and monitoring for processes using wasm3
ulimit -v [memory_limit_in_kb]
🧯 If You Can't Patch
- Implement rate limiting on WebAssembly module execution
- Deploy memory monitoring with automatic restart thresholds
🔍 How to Verify
Check if Vulnerable:
Check if wasm3 version includes commit 139076a or earlier. Run test with malformed UTF-8 WebAssembly module and monitor memory usage.Check Version:
Check git commit hash or version string in wasm3 source/buildVerify Fix Applied:
Update to latest wasm3 version and test with same malformed input - memory should remain stable.📡 Detection & Monitoring
Log Indicators:
- Unusual memory growth patterns
- Application crashes with out-of-memory errors
- Repeated wasm3 process restarts
Network Indicators:
- Unusual volume of WebAssembly module uploads/executions
SIEM Query:
source="application_logs" ("out of memory" OR "memory allocation failed") AND process="wasm3"