CVE-2021-39222

XSS in Talk

Severity Score

6.1

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Talk application was vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. For exploitation, a user would need to right-click on a malicious file and open the file in a new tab. Due the strict Content-Security-Policy shipped with Nextcloud, this issue is not exploitable on modern browsers supporting Content-Security-Policy. It is recommended that the Nextcloud Talk application is upgraded to patched versions 10.0.7, 10.1.4, 11.1.2, 11.2.0 or 12.0.0. As a workaround, use a browser that has support for Content-Security-Policy.

Nextcloud es una plataforma de productividad de código abierto y auto alojada. La aplicación Nextcloud Talk era susceptible a una vulnerabilidad de tipo Cross-Site Scripting (XSS) almacenada. Para una explotación, un usuario tendría que hacer clic con el botón derecho en un archivo malicioso y abrirlo en una nueva pestaña. Debido a la estricta política de seguridad de contenidos incluida en Nextcloud, este problema no es explotable en los navegadores modernos que soportan la política de seguridad de contenidos. Es recomendado actualizar la aplicación Nextcloud Talk a las versiones parcheadas 10.0.7, 10.1.4, 11.1.2, 11.2.0 o 12.0.0. Como solución, use un navegador que tenga soporte para Content-Security-Policy

*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

High

Privileges Required

Low

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

2021-08-16 CVE Reserved
2021-11-15 CVE Published
2024-07-31 EPSS Updated
2024-08-04 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-434: Unrestricted Upload of File with Dangerous Type

CAPEC

References (2)

URL	Tag	Source
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-xhxq-f4vg-jw5g	Third Party Advisory
https://github.com/nextcloud/spreed/pull/542	Third Party Advisory

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Nextcloud Search vendor "Nextcloud"		Talk Search vendor "Nextcloud" for product "Talk"				< 10.0.7 Search vendor "Nextcloud" for product "Talk" and version " < 10.0.7"		-		Affected
Nextcloud Search vendor "Nextcloud"		Talk Search vendor "Nextcloud" for product "Talk"				>= 10.1.0 < 10.1.4 Search vendor "Nextcloud" for product "Talk" and version " >= 10.1.0 < 10.1.4"		-		Affected
Nextcloud Search vendor "Nextcloud"		Talk Search vendor "Nextcloud" for product "Talk"				>= 11.0.0 < 11.1.2 Search vendor "Nextcloud" for product "Talk" and version " >= 11.0.0 < 11.1.2"		-		Affected