CVE-2021-39175 : What You Need to Know

HedgeDoc, a platform for writing and sharing markdown, was affected by a Cross-Site Scripting (XSS) vulnerability in the slide mode speaker-view feature.

Understanding CVE-2021-39175

This CVE outlines the details of a security vulnerability in HedgeDoc versions below 1.9.0 that allowed an unauthenticated attacker to inject arbitrary JavaScript into the speaker-notes in slide mode.

What is CVE-2021-39175?

The vulnerability enabled attackers to embed an iframe hosting malicious code into slides or the HedgeDoc instance on another page.

The Impact of CVE-2021-39175

CVSS Base Score: 8.1 (High)
Attack Vector: Network
Attack Complexity: Low
Confidentiality, Integrity Impact: High
User Interaction: Required
Privileges Required: None

Technical Details of CVE-2021-39175

The technical aspects of the vulnerability are as follows:

Vulnerability Description

The issue allowed unauthenticated attackers to inject arbitrary JavaScript into speaker-notes.

Affected Systems and Versions

Product: HedgeDoc
Vendor: HedgeDoc
Versions Affected: < 1.9.0

Exploitation Mechanism

Attackers could embed malicious iframes into slides or into the HedgeDoc instance on external pages.

Mitigation and Prevention

It is crucial to take immediate steps and implement long-term security practices to mitigate the risks associated with CVE-2021-39175.

Immediate Steps to Take

Upgrade HedgeDoc to version 1.9.0 to patch the vulnerability.

Long-Term Security Practices

Regularly update software and apply security patches promptly.
Educate users about recognizing and avoiding potential security risks.

Patching and Updates

Ensure all software components are up to date to prevent known vulnerabilities.