CVEvulnerability

CVE-2020-26287

8.7 HIGH Published 2020-12-29 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2020-12-29
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.7 HIGH — CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
CVSS 3.1 ([email protected])
8.7 HIGH — CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
CVSS 2.0 ([email protected])
4.3 MEDIUM — AV:N/AC:M/Au:N/C:N/I:P/A:N
Weaknesses
CWE-79

Description

HedgeDoc is a collaborative platform for writing and sharing markdown. In HedgeDoc before version 1.7.1 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. The problem is patched in HedgeDoc 1.7.1. As a workaround one can disallow `www.google-analytics.com` in the `Content-Security-Policy` header. Note that other ways to leverage the `script` tag injection might exist.

Affected configurations

• hedgedoc hedgedoc (< 1.7.1)

Related

Weakness · CWE (1)

  • CWE-79 Improper Neutralization of Input During Web Page Generation weakness

References