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CVE-2021-39220

Bypass of image blocking in Nextcloud Mail

Published: Oct 25, 2021Updated: Nov 21, 2024 Sources: CVE List NVDCWE-20
NVD MITRE
3.5CVSSLOW
EPSS Score
0.8%
Top 49.6%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:RS:UC:LI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:NIntegrity
None
A:NAvailability
None
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Weaknesses

CWE-20CWE-200

Affected Products

mailnextcloud
On-prem
Cloud & SaaS / saas-application
security-advisoriesnextcloud
SaaSSaaS Service
Cloud & SaaS / saas-application
nextcloudoss-projectDECloud & SaaSaka nextcloud server

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Collection
Initial Access
View detailed technique mapping

References

https://github.com/nextcloud/mail/pull/5470
github.com
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-6q9v-wm8r-rcv5
github.com
https://hackerone.com/reports/1308147
hackerone.com

Timeline

Published
Oct 25, 2021
Last Updated
Nov 21, 2024

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