// For flags

CVE-2021-29503

Improper Neutralization of Script-Related HTML Tags in Notes

Severity Score

6.1
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

HedgeDoc es una plataforma para escribir y compartir markdown.&#xa0;HedgeDoc versiones anteriores a 1.8.2, es vulnerable a un ataque de tipo cross-site scripting usando los metadatos YAML de una nota.&#xa0;Un atacante con acceso de escritura a una nota puede insertar etiquetas HTML en la sección de metadatos de Open Graph de la nota, resultando en que el frontend renderiza la etiqueta script como parte de la sección "(head)". A menos que su instancia impida a unos invitados editar unas notas, esta vulnerabilidad permite que atacantes no autentificados inyectan JavaScript en unas notas que permiten la edición de los invitados. Si su instancia impide a unos invitados editar unas notas, esta vulnerabilidad permite a atacantes autentificados inyectar JavaScript en cualquier página de notas a la que tengan acceso de escritura. Esta vulnerabilidad está parcheada en versión 1.8.2. Como solución, uno puede deshabilitar una edición de invitados hasta la próxima actualización

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-03-30 CVE Reserved
  • 2021-05-19 CVE Published
  • 2024-02-02 EPSS Updated
  • 2024-08-03 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
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)
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Hedgedoc
Search vendor "Hedgedoc"
Hedgedoc
Search vendor "Hedgedoc" for product "Hedgedoc"
< 1.8.2
Search vendor "Hedgedoc" for product "Hedgedoc" and version " < 1.8.2"
-
Affected