CVE-2021-39220

LOW

Nextcloud Mail < 1.10.4 - Privacy Filter Bypass via Relative Protocol Images

Title source: llm
STIX 2.1

Description

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.

References (3)

Core 3
Core References
Patch, Third Party Advisory x_refsource_misc
https://github.com/nextcloud/mail/pull/5470
Permissions Required x_refsource_misc
https://hackerone.com/reports/1308147

Scores

CVSS v3 3.5
EPSS 0.0026
EPSS Percentile 49.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N

Details

CWE
CWE-20 CWE-200
Status published
Products (1)
nextcloud/mail < 1.10.4
Published Oct 25, 2021
Tracked Since Feb 18, 2026