CVE-2021-21259 Information

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.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Reference

https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.2 https://github.com/hedgedoc/hedgedoc/commit/35b0d39a12aa35f27fba8c1f50b1886706e7efef https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-44w9-vm8p-3cxw https://github.com/hackmdio/codimd/issues/1648

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

REQUIRED

Confidentiality Impact

CHANGED

Integrity Impact

LOW

Availability Impact

LOW

Base Score

NONE

Base Severity

6.1