CVE-2023-38961
📋 TL;DR
A buffer overflow vulnerability in JerryScript v3.0.0 allows remote attackers to execute arbitrary code by exploiting the scanner_is_context_needed component. This affects systems running vulnerable versions of JerryScript, potentially leading to complete system compromise. The vulnerability is particularly dangerous because it can be triggered remotely without authentication.
💻 Affected Systems
- JerryScript
📦 What is this software?
Jerryscript by Jerryscript
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to full system compromise, data exfiltration, and persistent backdoor installation.
Likely Case
Application crash leading to denial of service, with potential for limited code execution in constrained environments.
If Mitigated
Application crash with no code execution if memory protections (ASLR, DEP) are properly implemented.
🎯 Exploit Status
The vulnerability requires crafting malicious JavaScript input but doesn't require authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v3.0.1 or later
Vendor Advisory: https://github.com/jerryscript-project/jerryscript/issues/5092
Restart Required: Yes
Instructions:
1. Check current JerryScript version. 2. Update to v3.0.1 or later via package manager or source compilation. 3. Restart all services using JerryScript. 4. Verify the update was successful.
🔧 Temporary Workarounds
Input Validation
allImplement strict input validation and sanitization for JavaScript input to JerryScript
Memory Protection
linuxEnable ASLR and DEP/PaX/NX protections at OS level
sysctl -w kernel.randomize_va_space=2
🧯 If You Can't Patch
- Isolate JerryScript instances in containers or VMs with minimal privileges
- Implement network segmentation to restrict access to vulnerable systems
🔍 How to Verify
Check if Vulnerable:
Check JerryScript version: jerry --version or examine package manager outputCheck Version:
jerry --versionVerify Fix Applied:
Verify version is v3.0.1 or later and test with known safe JavaScript inputs📡 Detection & Monitoring
Log Indicators:
- Segmentation fault errors
- Memory access violation logs
- Unexpected process termination
Network Indicators:
- Unusual JavaScript payloads in network traffic
- Multiple connection attempts with malformed data
SIEM Query:
source="application.log" AND ("segmentation fault" OR "buffer overflow" OR "jerryscript")