// For flags

CVE-2021-39220

Bypass of image blocking in Nextcloud Mail

Severity Score

3.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

Nextcloud is an open-source, self-hosted productivity platform The Nextcloud Mail application prior to versions 1.10.4 and 1.11.0 does by default not render images in emails to not leak the read state or user IP. The privacy filter failed to filter images with a relative protocol. It is recommended that the Nextcloud Mail application is upgraded to 1.10.4 or 1.11.0. There are no known workarounds aside from upgrading.

Nextcloud es una plataforma de productividad de código abierto y auto-alojada La aplicación Nextcloud Mail versiones anteriores a 1.10.4 y 1.11.0, no renderiza por defecto las imágenes en los correos electrónicos para no filtrar el estado de lectura o la IP del usuario. El filtro de privacidad no filtraba las imágenes con un protocolo relativo. Es recomendado actualizar la aplicación Nextcloud Mail a la versión 1.10.4 o 1.11.0. No se presentan soluciones conocidas aparte de la actualización

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
Single
Confidentiality
Partial
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-08-16 CVE Reserved
  • 2021-10-25 CVE Published
  • 2023-05-18 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-20: Improper Input Validation
  • CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Nextcloud
Search vendor "Nextcloud"
Mail
Search vendor "Nextcloud" for product "Mail"
< 1.10.4
Search vendor "Nextcloud" for product "Mail" and version " < 1.10.4"
-
Affected