CVE-2020-26287 : Vulnerability Insights and Analysis

HedgeDoc is a collaborative platform for writing and sharing markdown. In HedgeDoc before version 1.7.1, an attacker can inject arbitrary

script

tags in HedgeDoc notes using mermaid diagrams. This vulnerability allows for the execution of arbitrary JavaScript code on page load, potentially compromising the confidentiality and integrity of user data.

Understanding CVE-2020-26287

What is CVE-2020-26287?

CVE-2020-26287 is a stored Cross-site Scripting (XSS) vulnerability in HedgeDoc versions prior to 1.7.1. It enables attackers to inject malicious scripts into HedgeDoc notes through mermaid diagrams, leading to unauthorized execution of JavaScript code.

The Impact of CVE-2020-26287

The vulnerability has a CVSS base score of 8.7, indicating a high severity level. It poses a significant risk to confidentiality and integrity, requiring low privileges for exploitation and user interaction.

Technical Details of CVE-2020-26287

Vulnerability Description

The flaw allows attackers to insert

script

tags in HedgeDoc notes via mermaid diagrams, potentially executing arbitrary JavaScript code.

Affected Systems and Versions

Product: HedgeDoc
Vendor: HedgeDoc
Versions Affected: < 1.7.1

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Network
Privileges Required: Low
User Interaction: Required
Scope: Changed
Integrity Impact: High
Confidentiality Impact: High
Availability Impact: None

Mitigation and Prevention

Immediate Steps to Take

Upgrade HedgeDoc to version 1.7.1 or later to patch the vulnerability.
Disallow

www.google-analytics.com

in the

Content-Security-Policy

header as a temporary workaround.

Long-Term Security Practices

Regularly update software and apply security patches promptly.
Implement strict Content-Security-Policy rules to prevent script injections.
Conduct security audits and penetration testing to identify and address vulnerabilities.

Patching and Updates

Ensure that all instances of HedgeDoc are updated to version 1.7.1 or above to mitigate the risk of exploitation.