CVE-2022-1427
📋 TL;DR
CVE-2022-1427 is an out-of-bounds read vulnerability in mrb_obj_is_kind_of function in mruby, a lightweight Ruby implementation. This could allow attackers to read sensitive memory contents and potentially execute arbitrary code. Anyone using mruby versions prior to 3.2 is affected.
💻 Affected Systems
- mruby
📦 What is this software?
Mruby by Mruby
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Information disclosure through memory reading, potential denial of service, or limited code execution in constrained environments.
If Mitigated
Minimal impact if proper memory protections (ASLR, DEP) are enabled and the system is isolated.
🎯 Exploit Status
Exploitation requires triggering the vulnerable function with crafted input, which may require specific application conditions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: mruby 3.2 and later
Vendor Advisory: https://github.com/mruby/mruby/commit/a4d97934d51cb88954cc49161dc1d151f64afb6b
Restart Required: Yes
Instructions:
1. Update mruby to version 3.2 or later. 2. Recompile any applications using mruby. 3. Restart services using mruby.
🔧 Temporary Workarounds
Disable vulnerable functionality
allIf possible, avoid using mrb_obj_is_kind_of function or limit its exposure.
🧯 If You Can't Patch
- Implement strict input validation and sanitization for mruby scripts
- Isolate mruby execution in sandboxed environments or containers
🔍 How to Verify
Check if Vulnerable:
Check mruby version with 'mruby --version' or examine application dependencies for mruby < 3.2Check Version:
mruby --versionVerify Fix Applied:
Confirm mruby version is 3.2 or later and verify the commit a4d97934d51cb88954cc49161dc1d151f64afb6b is included📡 Detection & Monitoring
Log Indicators:
- Application crashes, memory access violations, or unusual mruby script execution patterns
Network Indicators:
- Unusual network connections from mruby processes
SIEM Query:
Process execution where command contains 'mruby' AND version < 3.2