Subject: [ASA-202109-1] hedgedoc: cross-site scripting

Arch Linux Security Advisory ASA-202109-1
=========================================

Severity: High
Date    : 2021-09-14
CVE-ID  : CVE-2021-39175
Package : hedgedoc
Type    : cross-site scripting
Remote  : Yes
Link    : https://security.archlinux.org/AVG-2331

Summary
=======

The package hedgedoc before version 1.9.0-1 is vulnerable to cross-site
scripting.

Resolution
==========

Upgrade to 1.9.0-1.

# pacman -Syu "hedgedoc>=1.9.0-1"

The problem has been fixed upstream in version 1.9.0.

Workaround
==========

None.

Description
===========

In HedgeDoc versions prior to 1.9.0, an unauthenticated attacker can
inject arbitrary JavaScript into the speaker-notes of the slide-mode
feature by embedding an iframe hosting the malicious code into the
slides or by embedding the HedgeDoc instance into another page.

Impact
======

An unauthenticated remote attacker could execute arbitrary JavaScript
code in the slide mode of HedgeDoc.

References
==========

https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-j748-779h-9697
https://github.com/hedgedoc/hedgedoc/pull/1369
https://github.com/hedgedoc/hedgedoc/pull/1375
https://github.com/hedgedoc/hedgedoc/pull/1513
https://security.archlinux.org/CVE-2021-39175