CVE-2018-12247 : Vulnerability Insights and Analysis

A problem has been found in mruby version 1.4.1 where a NULL pointer is accessed in the mrb_class function, linked to the use of .clone under specific circumstances.

Understanding CVE-2018-12247

This CVE involves a vulnerability in mruby version 1.4.1 that can lead to a NULL pointer dereference in mrb_class under certain conditions.

What is CVE-2018-12247?

The issue arises due to the mrb_obj_clone function in kernel.c only duplicating certain flags, excluding the MRB_FLAG_IS_FROZEN flag, such as the embedded flag.

The Impact of CVE-2018-12247

This vulnerability could be exploited to cause a denial of service or potentially execute arbitrary code on the affected system.

Technical Details of CVE-2018-12247

This section provides more in-depth technical details about the CVE.

Vulnerability Description

The problem lies in a NULL pointer dereference in the mrb_class function when using .clone, caused by the incomplete duplication of flags in the mrb_obj_clone function.

Affected Systems and Versions

Affected Version: mruby 1.4.1
Systems using mruby 1.4.1 are vulnerable to this issue.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting a specific scenario where .clone is used, leading to a NULL pointer dereference in the mrb_class function.

Mitigation and Prevention

It is crucial to take immediate steps to address and prevent the exploitation of this vulnerability.

Immediate Steps to Take

Update mruby to a patched version that addresses this vulnerability.
Monitor for any unusual activities on the system that could indicate exploitation.

Long-Term Security Practices

Regularly update software and libraries to the latest secure versions.
Implement code review processes to catch similar issues during development.

Patching and Updates

Apply patches provided by mruby to fix the vulnerability.