CVE-2021-32727

Nextcloud Android Client is the Android client for Nextcloud. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.16.1, the Nextcloud Android client skipped a step that involved the client checking if a private key belonged to a previously downloaded public certificate. If the Nextcloud instance served a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. The vulnerability is patched in version 3.16.1. As a workaround, do not add additional end-to-end encrypted devices to a user account.

• CWE-295
• CWE-295

• https://github.com/nextcloud/android/pull/8438Third Party Advisory
• https://github.com/nextcloud/end_to_end_encryption_rfc/blob/7f002996397faefb664019a97ebb0a1e210f64f0/RFC.md#further-devicesThird Party Advisory
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-5v33-r9cm-7736Third Party Advisory
• https://hackerone.com/reports/1189162Permissions Required
• https://github.com/nextcloud/android/pull/8438Third Party Advisory
• https://github.com/nextcloud/end_to_end_encryption_rfc/blob/7f002996397faefb664019a97ebb0a1e210f64f0/RFC.md#further-devicesThird Party Advisory
• https://github.com/nextcloud/security-advisories/security/advisories/GHSA-5v33-r9cm-7736Third Party Advisory
• https://hackerone.com/reports/1189162Permissions Required

Published

Jul 12, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2021-32721PowerMux is a drop-in replacement for Go's http.ServeMux. In…6.1
• CVE-2021-32722GlobalNewFiles is a mediawiki extension. Versions prior to 4…6.5
• CVE-2021-32723Prism is a syntax highlighting library. Some languages befor…6.5
• CVE-2021-32724check-spelling is a github action which provides CI spell ch…9.9
• CVE-2021-32725Nextcloud Server is a Nextcloud package that handles data st…5.3
• CVE-2021-32726Nextcloud Server is a Nextcloud package that handles data st…9.8
• CVE-2021-32728The Nextcloud Desktop Client is a tool to synchronize files …6.5
• CVE-2021-32729XWiki Platform is a generic wiki platform offering runtime s…5.4
• CVE-2021-3273Nagios XI below 5.7 is affected by code injection in the /na…7.2
• CVE-2021-32730XWiki Platform is a generic wiki platform offering runtime s…5.7
• CVE-2021-32731XWiki Platform is a generic wiki platform offering runtime s…5.3
• CVE-2021-32732### Impact It's possible to know if a user has or not an acc…6.5