CVE-2018-20615 : What You Need to Know

A vulnerability was found in the HAProxy versions 1.8.x and 1.9.x, specifically in the HTTP/2 protocol decoder. This vulnerability allows for a crash to occur due to an out-of-bounds read issue. The crash is triggered during the processing of the PRIORITY flag in a HEADERS frame. The issue arises from the fact that 5 additional bytes are required for this processing, however, the frame length is not properly checked to ensure the presence of these bytes.

Understanding CVE-2018-20615

This CVE identifies an out-of-bounds read issue in the HTTP/2 protocol decoder of HAProxy versions 1.8.x and 1.9.x.

What is CVE-2018-20615?

CVE-2018-20615 is a vulnerability in HAProxy versions 1.8.x and 1.9.x related to the processing of the PRIORITY flag in a HEADERS frame within the HTTP/2 protocol decoder.

The Impact of CVE-2018-20615

The vulnerability can lead to a crash due to an out-of-bounds read issue during the processing of the PRIORITY flag in a HEADERS frame.

Technical Details of CVE-2018-20615

This section provides more technical insights into the vulnerability.

Vulnerability Description

The issue in HAProxy versions 1.8.x and 1.9.x allows for a crash to occur because the processing of the PRIORITY flag in a HEADERS frame requires 5 additional bytes, which are not properly checked for presence in the frame.

Affected Systems and Versions

HAProxy versions 1.8.x and 1.9.x are affected by this vulnerability.

Exploitation Mechanism

The crash is triggered during the processing of the PRIORITY flag in a HEADERS frame due to the lack of proper validation for the required additional bytes.

Mitigation and Prevention

Protecting systems from CVE-2018-20615 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update HAProxy to a non-vulnerable version if available.
Monitor vendor advisories for patches and apply them promptly.
Implement network-level controls to mitigate potential exploitation.

Long-Term Security Practices

Regularly update and patch software to prevent known vulnerabilities.
Conduct security assessments and audits to identify and address weaknesses.
Educate staff on secure coding practices and awareness of potential threats.
Employ intrusion detection and prevention systems to monitor and block malicious activities.

Patching and Updates

Ensure that HAProxy is updated to a version that addresses the vulnerability to prevent exploitation.