CVE-2017-6181 Explained : Impact and Mitigation

A crafted regular expression can be used by remote attackers to cause a denial of service in the Onigmo regular expression library, specifically in the parse_char_class function of regparse.c. This vulnerability affects Ruby 2.4.0.

Understanding CVE-2017-6181

This CVE entry describes a vulnerability in the Onigmo regular expression library that can lead to a denial of service attack in Ruby 2.4.0.

What is CVE-2017-6181?

The parse_char_class function in regparse.c in the Onigmo library allows remote attackers to trigger a denial of service by causing deep recursion and crashing the application through a specially crafted regular expression.

The Impact of CVE-2017-6181

The vulnerability can be exploited by remote attackers to crash applications using Ruby 2.4.0, potentially leading to service disruption and system instability.

Technical Details of CVE-2017-6181

This section provides more technical insights into the vulnerability.

Vulnerability Description

The parse_char_class function in regparse.c in the Onigmo library allows remote attackers to cause a denial of service (deep recursion and application crash) via a crafted regular expression.

Affected Systems and Versions

Ruby 2.4.0

Exploitation Mechanism

Remote attackers can exploit this vulnerability by using a specially crafted regular expression to trigger deep recursion, leading to an application crash.

Mitigation and Prevention

Protecting systems from CVE-2017-6181 requires immediate actions and long-term security practices.

Immediate Steps to Take

Apply patches or updates provided by the vendor to mitigate the vulnerability.
Monitor and restrict access to potentially vulnerable systems.

Long-Term Security Practices

Regularly update software and libraries to ensure the latest security fixes are in place.
Implement network security measures to detect and block malicious traffic.

Patching and Updates

Stay informed about security advisories and updates from Ruby to apply patches promptly.