CVE-2020-26239 : Exploit Details and Defense Strategies

Scratch Addons before version 1.3.2 is vulnerable to DOM-based XSS due to incorrect regular expressions in the More Links addon.

Understanding CVE-2020-26239

Scratch Addons, a WebExtension for Chrome and Firefox, is susceptible to a Cross-Site Scripting (XSS) vulnerability.

What is CVE-2020-26239?

Scratch Addons version < 1.3.2 is affected by a DOM-based XSS issue.
The vulnerability arises from incorrect regular expressions in the More Links addon.

The Impact of CVE-2020-26239

CVSS Score: 7.6 (High Severity)
Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: Required
Scope: Changed
Confidentiality Impact: Low
Integrity Impact: High
Availability Impact: None

Technical Details of CVE-2020-26239

The technical aspects of the vulnerability.

Vulnerability Description

Scratch Addons < 1.3.2 is prone to DOM-based XSS.

Affected Systems and Versions

Product: ScratchAddons
Vendor: ScratchAddons
Versions Affected: < 1.3.2

Exploitation Mechanism

Incorrect regular expressions in the More Links addon lead to unescaped HTML-escaped values, enabling XSS.

Mitigation and Prevention

Protective measures against CVE-2020-26239.

Immediate Steps to Take

Update Scratch Addons to version 1.3.2 to mitigate the vulnerability.
Disable the More Links addon through the extension's settings.

Long-Term Security Practices

Regularly update browser extensions to the latest versions.
Educate users on safe browsing practices to prevent XSS attacks.

Patching and Updates

Ensure automatic updates are enabled for browser extensions to receive security patches.