CVE-2019-17420 : What You Need to Know

A parsing error in the HTTP protocol of OISF LibHTP prior to version 0.5.31, which is utilized in Suricata 4.1.4 and other software, results in the http_header signature failing to produce an alert when encountering a response that ends with a single \r\n.

Understanding CVE-2019-17420

This CVE involves a vulnerability in OISF LibHTP that affects Suricata and other software.

What is CVE-2019-17420?

CVE-2019-17420 is a parsing error in the HTTP protocol of OISF LibHTP before version 0.5.31, leading to a failure in producing alerts for specific responses.

The Impact of CVE-2019-17420

The vulnerability can potentially allow malicious actors to evade detection mechanisms by exploiting the parsing error in the HTTP protocol.

Technical Details of CVE-2019-17420

This section provides more in-depth technical insights into the CVE.

Vulnerability Description

The issue lies in the HTTP protocol parsing error in OISF LibHTP, causing the http_header signature to not trigger alerts for responses ending with a single \r\n.

Affected Systems and Versions

OISF LibHTP versions prior to 0.5.31
Suricata 4.1.4 and potentially other software utilizing the vulnerable library

Exploitation Mechanism

Attackers can exploit this vulnerability to craft responses that end with a single \r\n, evading detection mechanisms that rely on the http_header signature.

Mitigation and Prevention

Protecting systems from CVE-2019-17420 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update OISF LibHTP to version 0.5.31 or newer.
Ensure Suricata and other affected software are patched with the latest updates.

Long-Term Security Practices

Regularly monitor for security advisories related to OISF LibHTP and Suricata.
Implement network intrusion detection best practices to enhance overall security posture.

Patching and Updates

Apply patches and updates provided by OISF LibHTP and Suricata to address the vulnerability effectively.