CVE-2022-1212
📋 TL;DR
CVE-2022-1212 is a use-after-free vulnerability in mruby's str_escape function that could allow attackers to execute arbitrary code. This affects applications using mruby versions prior to 3.2. The vulnerability is particularly dangerous due to its high CVSS score of 9.8.
💻 Affected Systems
- mruby
📦 What is this software?
Mruby by Mruby
Mruby by Mruby
Mruby by Mruby
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with remote code execution leading to data theft, ransomware deployment, or complete system takeover.
Likely Case
Application crash leading to denial of service, with potential for limited code execution in memory-constrained environments.
If Mitigated
Application crash without code execution if memory protections like ASLR are effective.
🎯 Exploit Status
Exploitation requires triggering the vulnerable str_escape function with specific inputs.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: mruby 3.2 and later
Vendor Advisory: https://github.com/mruby/mruby/commit/3cf291f72224715942beaf8553e42ba8891ab3c6
Restart Required: Yes
Instructions:
1. Update mruby to version 3.2 or later. 2. Recompile any applications using mruby. 3. Restart affected services.
🔧 Temporary Workarounds
Disable vulnerable functionality
allAvoid using str_escape function in application code if possible.
🧯 If You Can't Patch
- Implement strict input validation to prevent triggering the vulnerable code path.
- Deploy memory protection mechanisms like ASLR and DEP to reduce exploit success.
🔍 How to Verify
Check if Vulnerable:
Check mruby version with 'mruby --version' or examine application dependencies.Check Version:
mruby --versionVerify Fix Applied:
Confirm mruby version is 3.2 or later and verify the commit 3cf291f72224715942beaf8553e42ba8891ab3c6 is applied.📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory access violations
- Unexpected process terminations
Network Indicators:
- Unusual network connections from mruby processes
SIEM Query:
Process termination events from mruby applications OR memory access violation logs