An issue was discovered in ownCloud owncloud/core before 10.13.1. An attacker can access, modify, or delete any file without authentication if the username of a victim is known, and the victim has no signing-key configured. This occurs because pre-signed URLs can be accepted even when no signing-key is configured for the owner of the files. The earliest affected version is 10.6.0.

The Docker image of ownCloud Server through 10.11 contains a misconfiguration that renders the trusted_domains config useless. This could be abused to spoof the URL in password-reset e-mail messages.

ownCloud owncloud/core before 10.10.0 Improperly Removes Sensitive Information Before Storage or Transfer.

Session fixation on password protected public links in the ownCloud Server before 10.8.0 allows an attacker to bypass the password protection when they can force a target client to use a controlled cookie.

A receiver of a federated share with access to the database with ownCloud version before 10.8 could update the permissions and therefore elevate their own permissions.

The shareinfo controller in the ownCloud Server before 10.8.0 allows an attacker to bypass the permission checks for upload only shares and list metadata about the share.

The public share controller in the ownCloud server before version 10.8.0 allows a remote attacker to see the internal path and the username of a public share by including invalid characters in the URL.

ownCloud Server before 10.3.0 allows an attacker, who has received non-administrative access to a group share, to remove everyone else's access to that share.

An issue was discovered in ownCloud before 10.4. An attacker can bypass authentication on a password-protected image by displaying its preview.

An issue was discovered in ownCloud before 10.4. Because of an SSRF issue (via the apps/files_sharing/external remote parameter), an authenticated attacker can interact with local services blindly (aka Blind SSRF) or conduct a Denial Of Service attack.

Deleting users with certain names caused system files to be deleted. Risk is higher for systems which allow users to register themselves and have the data directory in the web root. This affects ownCloud/core versions < 10.6.

The CSRF (Cross Site Request Forgery) token check was improperly implemented on cookie authenticated requests against some ocs API endpoints. This affects ownCloud/core version < 10.6.

ownCloud (Core) before 10.5 allows XSS in login page 'forgot password.'

An attacker is logged in as a normal user and can somehow make admin to delete shared folders in ownCloud Server before 10.0.2.

A logical error in ownCloud Server before 10.0.2 caused disclosure of valid share tokens for public calendars. Thus granting an attacker potentially access to publicly shared calendars without knowing the share token.

Inadequate escaping lead to XSS vulnerability in the search module in ownCloud Server before 8.2.12, 9.0.x before 9.0.10, 9.1.x before 9.1.6, and 10.0.x before 10.0.2. To be exploitable a user has to write or paste malicious content into the search dialogue.

ownCloud Server before 8.2.12, 9.0.x before 9.0.10, 9.1.x before 9.1.6, and 10.0.x before 10.0.2 are vulnerable to XSS on error pages by injecting code in url parameters.

Nextcloud Server before 9.0.54 and 10.0.1 & ownCloud Server before 9.1.2, 9.0.6, and 8.2.9 suffer from SMB User Authentication Bypass. Nextcloud/ownCloud include an optional and not by default enabled SMB authentication component that allows authenticating users against an SMB server. This backend is implemented in a way that tries to connect to a SMB server and if that succeeded consider the user logged-in. The backend did not properly take into account SMB servers that have any kind of anonymous auth configured. This is the default on SMB servers nowadays and allows an unauthenticated attacker to gain access to an account without valid credentials. Note: The SMB backend is disabled by default and requires manual configuration in the Nextcloud/ownCloud config file. If you have not configured the SMB backend then you're not affected by this vulnerability.

Nextcloud Server before 9.0.52 & ownCloud Server before 9.0.4 are not properly verifying restore privileges when restoring a file. The restore capability of Nextcloud/ownCloud was not verifying whether a user has only read-only access to a share. Thus a user with read-only access was able to restore old versions.

Nextcloud Server before 9.0.52 & ownCloud Server before 9.0.4 are not properly verifying edit check permissions on WebDAV copy actions. The WebDAV endpoint was not properly checking the permission on a WebDAV COPY action. This allowed an authenticated attacker with access to a read-only share to put new files in there. It was not possible to modify existing files.