CVE-2021-29503

HedgeDoc is a platform to write and share markdown. HedgeDoc before version 1.8.2 is vulnerable to a cross-site scripting attack using the YAML-metadata of a note. An attacker with write access to a note can embed HTML tags in the Open Graph metadata section of the note, resulting in the frontend rendering the script tag as part of the `<head>` section. Unless your instance prevents guests from editing notes, this vulnerability allows unauthenticated attackers to inject JavaScript into notes that allow guest edits. If your instance prevents guests from editing notes, this vulnerability allows authenticated attackers to inject JavaScript into any note pages they have write-access to. This vulnerability is patched in version 1.8.2. As a workaround, one can disable guest edits until the next update.

CVSS v3 6.1 MEDIUM
CVSS v2.0 4.3 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

4.3^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:M/Au:N/C:N/I:P/A:N

Exploitability : 8.6 / Impact : 2.9

Access Vector NETWORK

Access Complexity MEDIUM

Authentication NONE

Confidentiality Impact NONE

Integrity Impact PARTIAL

Availability Impact NONE

References

Link	Resource
https://github.com/hedgedoc/hedgedoc/commit/01dad5821ee28377ebe640c6c72c3e0bb0d51ea7	Patch Third Party Advisory
https://github.com/hedgedoc/hedgedoc/releases/tag/1.8.2	Third Party Advisory
https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-gjg7-4j2h-94fq	Patch Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:hedgedoc:hedgedoc:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2021-05-19 20:15

Updated : 2024-02-28 18:28

NVD link : CVE-2021-29503

Mitre link : CVE-2021-29503

CVE.ORG link : CVE-2021-29503

JSON object : View

Products Affected

hedgedoc

hedgedoc

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-80

Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

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