Insecure randomness for default password in file sharing when password policy app is disabled

Description

Impact

The generated fallback password when creating a share was using a weak complexity, so when the sharer did not change it the password would be guessable in an acceptable time frame.

Patches

It is recommended that the Nextcloud Server is upgraded to 24.0.10 or 25.0.4
It is recommended that the Nextcloud Enterprise Server is upgraded to 23.0.14 or 24.0.10 or 25.0.4

Workarounds

• Enable password policy app
• Overwrite the default password when creating a share

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 support.nextcloud.com