CVE-2021-21259 Detail

Current 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. ### Workarounds Disallow loading JavaScript from 3rd party sites using the `Content-Security-Policy` header. Note that this will break some embedded content. ### References This issue was discovered by @TobiasHoll and reported to hackmdio/codimd: https://github.com/hackmdio/codimd/issues/1648 ### For more information If you have any questions or comments about this advisory: * Open an topic on our community forum * Join our matrix room


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score matches with CNA score
CNA:  GitHub, Inc.
Base Score:  7.4 HIGH
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: The NVD and the CNA have provided the same score. When this occurs only the CNA information is displayed, but the Acceptance Level icon for the CNA is given a checkmark to signify NVD concurrence.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/hedgedoc/hedgedoc/commit/35b0d39a12aa35f27fba8c1f50b1886706e7efef Patch  Third Party Advisory 
https://github.com/hedgedoc/hedgedoc/releases/tag/1.7.2 Release Notes  Third Party Advisory 
https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-44w9-vm8p-3cxw Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') Provider acceptance level GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-21259
NVD Published Date:
01/22/2021
NVD Last Modified:
02/01/2021
Source:
GitHub, Inc.