A hedgedoc security update has been released for Arch Linux.

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