CVE-2019-18856 Explained : Impact and Mitigation

Drupal SVG Sanitizer module versions 8.x-1.0-alpha1 and earlier are vulnerable to Denial of Service due to mishandling of external resource access.

Understanding CVE-2019-18856

This CVE involves a vulnerability in the SVG Sanitizer module for Drupal versions 8.x-1.0-alpha1 and earlier, leading to a Denial of Service risk.

What is CVE-2019-18856?

This CVE identifies a Denial of Service vulnerability in the SVG Sanitizer module for Drupal versions 8.x-1.0-alpha1 and earlier. The issue arises from improper handling of access to external resources when using an SVG use element.

The Impact of CVE-2019-18856

The vulnerability can be exploited to cause a Denial of Service, potentially disrupting the availability of affected Drupal websites.

Technical Details of CVE-2019-18856

The technical aspects of the vulnerability are as follows:

Vulnerability Description

The vulnerability in the SVG Sanitizer module for Drupal versions 8.x-1.0-alpha1 and earlier allows for a Denial of Service attack due to mishandling of external resource access with SVG use elements.

Affected Systems and Versions

Affected Product: Drupal SVG Sanitizer module
Affected Versions: 8.x-1.0-alpha1 and earlier

Exploitation Mechanism

The vulnerability can be exploited by an attacker to trigger a Denial of Service condition by manipulating external resource access through SVG use elements.

Mitigation and Prevention

To address CVE-2019-18856, consider the following mitigation strategies:

Immediate Steps to Take

Update the Drupal SVG Sanitizer module to a non-vulnerable version.
Implement network-level protections to mitigate potential Denial of Service attacks.

Long-Term Security Practices

Regularly monitor and apply security updates for Drupal modules.
Conduct security assessments to identify and address vulnerabilities proactively.

Patching and Updates

Apply patches provided by Drupal for the SVG Sanitizer module to fix the vulnerability and enhance security measures.