Impact
An attacker can inject arbitrary script tags in HedgeDoc notes using mermaid diagrams. Our content security policy prevents loading scripts from most locations, but www.google-analytics.com is allowed. Using Google Tag Manger it is possible to inject arbitrary JavaScript and execute it on page load.
Depending on the configuration of the instance, the attacker may not need authentication to create or edit notes.
Patches
The problem is patched in HedgeDoc 1.7.1.
Workarounds
Disallow www.google-analytics.com in the Content-Security-Policy header. Note that other ways to leverage the script tag injection might exist.
References
For more information
If you have any questions or comments about this advisory:
Alemmi Analyst
Impact
An attacker can inject arbitrary
scripttags in HedgeDoc notes using mermaid diagrams. Our content security policy prevents loading scripts from most locations, butwww.google-analytics.comis allowed. Using Google Tag Manger it is possible to inject arbitrary JavaScript and execute it on page load.Depending on the configuration of the instance, the attacker may not need authentication to create or edit notes.
Patches
The problem is patched in HedgeDoc 1.7.1.
Workarounds
Disallow
www.google-analytics.comin theContent-Security-Policyheader. Note that other ways to leverage thescripttag injection might exist.References
For more information
If you have any questions or comments about this advisory: