CVE Tools
Sign in

CVE-2021-32728

End-to-end encryption device setup did not verify public key

Published: Aug 18, 2021Updated: Nov 21, 2024 Sources: CVE List NVD BDUCWE-295
NVD MITRE
6.5CVSSMEDIUM
EPSS Score
0.9%
Top 46.6%
CISA KEV
Not in KEV
Exploits
2 Known
Remediation
Patch Available

Description

The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading.

CVSS Vector Breakdown

AV:NAC:LPR:LUI:NS:UC:HI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:NIntegrity
None
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-295

Affected Products

security-advisoriesnextcloud
SaaSSaaS Service
Cloud & SaaS / saas-application
Debian GNU/LinuxСообщество свободного программного обеспечения
On-premOS
Operating Systems / linux-distro
NextcloudNextcloud GmbH
SaaS
Cloud & SaaS / saas-application
desktopnextcloud
On-premDesktop App
Cloud & SaaS / saas-application
debian linuxdebian
On-premOS
Operating Systems / linux-distro
nextcloudoss-projectDECloud & SaaSaka nextcloud server
сообщество свободного программного обеспеченияoss-projectOperating Systemsaka сообщество свободного программного обеспечения, fsf
nextcloud gmbhcommercialDECloud & SaaSaka nextcloud server, nextcloud enterprise server, nextcloud calendar
debianoss-projectGBOperating Systemsaka debian gnu/linux

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

2 exploit sources identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available

MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://hackerone.com/reports/1189162
hackerone.com
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5
github.com
https://github.com/nextcloud/desktop/pull/3338
github.com
and 6 more references View all →

Timeline

Published
Aug 18, 2021
Last Updated
Nov 21, 2024

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2021-32728 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows