CVE-2023-23086
📋 TL;DR
CVE-2023-23086 is a critical buffer overflow vulnerability in MojoJson v1.2.3 that allows remote attackers to execute arbitrary code by exploiting the SkipString function. This affects any application using the vulnerable MojoJson library version. Attackers can potentially take full control of affected systems.
💻 Affected Systems
- MojoJson
📦 What is this software?
Mojojson by Mojojson Project
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining root/admin privileges, data exfiltration, ransomware deployment, and persistent backdoor installation.
Likely Case
Remote code execution leading to application compromise, data theft, and lateral movement within the network.
If Mitigated
Denial of service or application crash if exploit fails, but successful exploitation still possible with proper payload.
🎯 Exploit Status
The vulnerability is in a core parsing function and requires minimal exploitation complexity. Public GitHub issues demonstrate the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.2.4 or later
Vendor Advisory: https://github.com/scottcgi/MojoJson/issues/2
Restart Required: Yes
Instructions:
1. Update MojoJson to version 1.2.4 or later. 2. Rebuild and redeploy any applications using the library. 3. Restart affected services.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation and size limits on JSON data before passing to MojoJson parser
Memory Protection Controls
allEnable ASLR, DEP, and stack canaries at the OS/compiler level to make exploitation more difficult
gcc -fstack-protector-all -D_FORTIFY_SOURCE=2 -O2
Windows: Enable Data Execution Prevention (DEP)
🧯 If You Can't Patch
- Network segmentation: Isolate systems using vulnerable MojoJson version from untrusted networks
- Implement WAF rules to block suspicious JSON payloads and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check package.json or build configuration for MojoJson version 1.2.3. Review application dependencies for this specific version.Check Version:
npm list mojojson (for Node.js) or check package manager output for installed versionVerify Fix Applied:
Confirm MojoJson version is 1.2.4 or later in dependencies. Test JSON parsing functionality with various inputs.📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation faults
- Unusual process spawning from JSON parsing services
- Memory access violation errors
Network Indicators:
- Unusually large JSON payloads to services
- Repeated connection attempts with malformed JSON
SIEM Query:
source="application.log" AND ("segmentation fault" OR "buffer overflow" OR "MojoJson")