OAuth2 client_secret stored in plain text in the database

Description

Impact

When an attacker got access to the database or a backup of the database they could use the client secrets to use the OAuth2 logins on third party services linked with the Nextcloud server.

Patches

It is recommended that the Nextcloud Server is upgraded to 25.0.8, 26.0.3 or 27.0.1
It is recommended that the Nextcloud Enterprise Server is upgraded to 25.0.8, 26.0.3 or 27.0.1

Workarounds

• No workaround available

References

• HackerOne
• PullRequest

For more information

If you have any questions or comments about this advisory:

• Create a post in nextcloud/security-advisories
• Customers: Open a support ticket at portal.nextcloud.com