CVE-2021-21259
7.4 · HIGHOverview
CVE-2021-21259 is a high-severity vulnerability affecting hedgedoc hedgedoc. It was published on January 22, 2021 and has a CVSS 3.1 base score of 7.4 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.4, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
HedgeDoc is open source software which lets you create real-time collaborative markdown notes. In HedgeDoc before version 1.7.2, an attacker can inject arbitrary JavaScript into a HedgeDoc note, which is executed when the note is viewed in slide mode. Depending on the configuration of the instance, the attacker may not need authentication to create or edit notes. The problem is patched in HedgeDoc 1.7.2. As a workaround, disallow loading JavaScript from 3rd party sites using the `Content-Security-Policy` header. Note that this will break some embedded content.
Remediation
Check the references section for vendor advisories and patches from hedgedoc. Update hedgedoc to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| hedgedoc | hedgedoc | >= 0, < 1.7.2 | Affected |
References
Frequently Asked Questions
What is CVE-2021-21259?
CVE-2021-21259 is a high-severity vulnerability affecting hedgedoc hedgedoc. It was published on January 22, 2021 and has a CVSS 3.1 base score of 7.4 (HIGH).
How severe is CVE-2021-21259?
This vulnerability has a CVSS 3.1 base score of 7.4, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-21259?
Check the references section for vendor advisories and patches from hedgedoc. Update hedgedoc to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-21259?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-21259 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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