CVE-2020-23323
📋 TL;DR
CVE-2020-23323 is a critical heap buffer overflow vulnerability in JerryScript's regular expression parser that allows remote code execution. Attackers can exploit this by providing specially crafted JavaScript input containing escape sequences in regular expressions. This affects any application or device using vulnerable versions of the JerryScript JavaScript engine.
💻 Affected Systems
- JerryScript JavaScript engine
📦 What is this software?
Jerryscript by Jerryscript
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with full system compromise, allowing attackers to execute arbitrary code with the privileges of the JerryScript process.
Likely Case
Remote code execution leading to application compromise, data theft, or system takeover in affected environments.
If Mitigated
Denial of service or application crash if exploit attempts are blocked or fail, but system remains intact.
🎯 Exploit Status
The vulnerability is in the core parser and requires minimal exploitation complexity. Public GitHub issues demonstrate the crash condition.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: JerryScript 2.3.0 and later
Vendor Advisory: https://github.com/jerryscript-project/jerryscript/issues/3871
Restart Required: Yes
Instructions:
1. Update JerryScript to version 2.3.0 or later. 2. Recompile any applications using JerryScript. 3. Restart services using the updated library.
🔧 Temporary Workarounds
Input validation for regular expressions
allValidate and sanitize all regular expression inputs before passing to JerryScript parser
Disable regular expression parsing if not needed
allConfigure applications to disable or limit regular expression functionality
🧯 If You Can't Patch
- Network segmentation to isolate systems using JerryScript
- Implement strict input validation and sanitization for all JavaScript inputs
🔍 How to Verify
Check if Vulnerable:
Check if application uses JerryScript version 2.2.0 or earlier by examining dependencies or running 'strings' on binaries for JerryScript referencesCheck Version:
For Linux systems: 'ldconfig -p | grep jerry' or check package manager: 'dpkg -l | grep jerry' or 'rpm -qa | grep jerry'Verify Fix Applied:
Verify JerryScript version is 2.3.0 or later by checking library version or using package manager queries📡 Detection & Monitoring
Log Indicators:
- Segmentation faults or abnormal termination of JerryScript processes
- Memory corruption errors in application logs
- Unusual regular expression patterns in input logs
Network Indicators:
- Unusual network connections from JerryScript processes
- Exploit attempts containing crafted regular expressions
SIEM Query:
process_name:"jerry" AND (event_type:"crash" OR memory:"corruption" OR error:"segmentation fault")