CVE-2025-14956
📋 TL;DR
This CVE describes a heap-based buffer overflow vulnerability in WebAssembly Binaryen's WasmBinaryReader::readExport function. Attackers can exploit this to potentially execute arbitrary code or cause denial of service on systems running vulnerable versions. The vulnerability affects local hosts where Binaryen processes untrusted WebAssembly modules.
💻 Affected Systems
- WebAssembly Binaryen
📦 What is this software?
Binaryen by Webassembly
⚠️ Risk & Real-World Impact
Worst Case
Arbitrary code execution leading to complete system compromise, data theft, or persistent backdoor installation.
Likely Case
Application crash or denial of service when processing malicious WebAssembly modules.
If Mitigated
Limited impact with proper sandboxing and input validation, potentially just application instability.
🎯 Exploit Status
Exploit requires crafting malicious WebAssembly binary and local access to trigger the buffer overflow.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit 4f52bff8c4075b5630422f902dd92a0af2c9f398 and later
Vendor Advisory: https://github.com/WebAssembly/binaryen/commit/4f52bff8c4075b5630422f902dd92a0af2c9f398
Restart Required: Yes
Instructions:
1. Update Binaryen to version after commit 4f52bff8c4075b5630422f902dd92a0af2c9f398. 2. Rebuild any applications using Binaryen. 3. Restart affected services.
🔧 Temporary Workarounds
Input Validation
allImplement strict validation of WebAssembly binary inputs before processing with Binaryen.
Sandbox Execution
linuxRun Binaryen in a sandboxed environment with limited privileges.
docker run --security-opt=no-new-privileges --cap-drop=ALL -it binaryen
🧯 If You Can't Patch
- Isolate Binaryen processing to dedicated, non-privileged systems with network segmentation.
- Implement strict monitoring for abnormal process behavior or crashes when processing WebAssembly modules.
🔍 How to Verify
Check if Vulnerable:
Check Binaryen version: binaryen --version should show version <= 125 or commit hash before 4f52bff8c4075b5630422f902dd92a0af2c9f398.Check Version:
binaryen --versionVerify Fix Applied:
Verify Binaryen version > 125 or commit includes 4f52bff8c4075b5630422f902dd92a0af2c9f398. Test with known malicious WebAssembly module to ensure no crash.📡 Detection & Monitoring
Log Indicators:
- Segmentation fault logs from Binaryen processes
- Abnormal termination of WebAssembly processing services
Network Indicators:
- Unusual local process communication patterns when WebAssembly modules are processed
SIEM Query:
process.name:"binaryen" AND (event.action:"segmentation_fault" OR event.action:"crash")🔗 References
- https://github.com/WebAssembly/binaryen/
- https://github.com/WebAssembly/binaryen/commit/4f52bff8c4075b5630422f902dd92a0af2c9f398
- https://github.com/WebAssembly/binaryen/issues/8089
- https://github.com/WebAssembly/binaryen/pull/8092
- https://github.com/oneafter/1204/blob/main/hbf
- https://vuldb.com/?ctiid.337592
- https://vuldb.com/?id.337592
- https://vuldb.com/?submit.717315
