CVE-2020-26211 Explained : Impact and Mitigation

In BookStack before version 0.30.4, a user with permissions to edit a page could insert JavaScript code through the use of

javascript:

URIs within a link or form which would run when clicked or submitted. This vulnerability also allowed users to insert a meta tag for silent redirection. The issue is fixed in version 0.30.4.

Understanding CVE-2020-26211

This CVE involves a Cross-Site Scripting vulnerability in BookStack.

What is CVE-2020-26211?

CVE-2020-26211 is a security vulnerability in BookStack that allowed users to insert malicious JavaScript code or meta tags, potentially leading to unauthorized actions.

The Impact of CVE-2020-26211

The vulnerability had a CVSS base score of 7.7 (High severity) with confidentiality, integrity, and availability impacts.

Technical Details of CVE-2020-26211

This section provides more technical insights into the CVE.

Vulnerability Description

Users with edit permissions could insert JavaScript code or meta tags, enabling potential malicious activities.

Affected Systems and Versions

Product: BookStack
Vendor: BookStackApp
Versions Affected: < 0.30.4

Exploitation Mechanism

Attack Complexity: High
Attack Vector: Network
Privileges Required: Low
User Interaction: Required
Scope: Changed
Exploitation Impact: Confidentiality, Integrity

Mitigation and Prevention

Protect your systems from CVE-2020-26211 with these strategies.

Immediate Steps to Take

Upgrade to BookStack version 0.30.4 to fix the vulnerability.
Limit page edit permissions to trusted users as a temporary workaround.

Long-Term Security Practices

Regularly update software to the latest versions.
Educate users on safe practices to prevent XSS attacks.

Patching and Updates

Ensure timely installation of security patches and updates.