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TI-2021-12396 Aliases CVE-2021-32728

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

Priority LOW 30CWE-295Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Spoofing
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-295.

Summary

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.

Why it matters now

EPSS 0.00851 58th percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix Fixed security-advisories (nextcloud): 3.3.0

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
nextcloudsecurity-advisoriesbefore 3.3.03.3.0Patch availableCNA
  • security-advisories Vendornextcloud Affected before 3.3.0 Fixed in 3.3.0 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:nextcloud:desktop:*:*:*:*:*:*:*:*before 3.3.0Vulnerablenextcloud
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*10.0VulnerableDebian
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*11.0VulnerableDebian
  • cpe:2.3:a:nextcloud:desktop:*:*:*:*:*:*:*:* Versions before 3.3.0 Vulnerable ·nextcloud
  • cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
  • cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* Versions 11.0 Vulnerable ·Debian

Remediation

  • Fix · CNA security-advisories (nextcloud) Fixed in 3.3.0

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-32728

References

Exploit 2

Patch 1

Advisory 1

  • TI-2022-18709 Cross-site scripting (XSS) in Nextcloud Desktop Client CVSS 3.1MEDIUM 6.1
  • TI-2022-18708 Cross-site scripting (XSS) in Nextcloud Desktop Client CVSS 3.1MEDIUM 5.4
  • TI-2022-18707 Cross-site Scripting (XSS) in Nexcloud Desktop Client CVSS 3.1MEDIUM 5.4
  • TI-2022-18710 nextcloudcmd incorrectly trusts bad TLS certificates CVSS 3.1MEDIUM 4.7
  • TI-2020-06645 Path traversal in Desktop Client CVSS 3.1MEDIUM 6.8
  • TI-2021-05740 Injection in Nextcloud Desktop Client CVSS 3.1HIGH 8.8
See all 26 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences