CVE-2019-19204 : Exploit Details and Defense Strategies

A vulnerability has been found in Oniguruma 6.x prior to version 6.9.4_rc2, leading to a heap-based buffer over-read.

Understanding CVE-2019-19204

This CVE identifies a specific vulnerability in the Oniguruma library.

What is CVE-2019-19204?

CVE-2019-19204 is a vulnerability in Oniguruma 6.x before version 6.9.4_rc2, specifically in the fetch_interval_quantifier function in regparse.c.

The Impact of CVE-2019-19204

The vulnerability arises from the improper use of PFETCH without verifying PEND, resulting in a heap-based buffer over-read.

Technical Details of CVE-2019-19204

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

Vulnerability Description

The issue occurs in the fetch_interval_quantifier function, previously known as fetch_range_quantifier, where PFETCH is called without checking PEND, leading to a heap-based buffer over-read.

Affected Systems and Versions

Product: Oniguruma 6.x
Versions: Prior to 6.9.4_rc2

Exploitation Mechanism

The vulnerability is exploited by utilizing PFETCH without proper verification of PEND, allowing attackers to trigger a heap-based buffer over-read.

Mitigation and Prevention

Protecting systems from CVE-2019-19204 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Oniguruma to version 6.9.4_rc2 or later to mitigate the vulnerability.
Monitor vendor advisories and security mailing lists for any patches or updates.

Long-Term Security Practices

Regularly update software and libraries to the latest versions.
Implement secure coding practices to prevent similar vulnerabilities in the future.

Patching and Updates

Ensure timely application of patches and updates provided by the software vendor to address CVE-2019-19204.