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.

Improper Authentication in Nextcloud Server prior to version 12.0.3 would allow an attacker that obtained user credentials to bypass the 2 Factor Authentication.

Nextcloud Server is a self hosted personal cloud system, and the Nextcloud Groupfolders app provides admin-configured folders shared by everyone in a group or team. In Nextcloud Server prior to 30.0.2, 29.0.9, and 28.0.1, Nextcloud Enterprise Server prior to 30.0.2 and 29.0.9, and Nextcloud Groupfolders app prior to 18.0.3, 17.0.5, and 16.0.11, the absence of quota checking on attachments allowed logged-in users to upload files exceeding the group folder quota. Nextcloud Server versions 30.0.2 and 29.0.9, Nextcloud Enterprise Server versions 30.0.2, 29.0.9, or 28.0.12, and Nextcloud Groupfolders app 18.0.3, 17.0.5, and 16.0.11 fix the issue. No known workarounds are available.

Nextcloud Mail is a mail app for Nextcloud. In versions prior to 1.9.6, the Nextcloud Mail application does not, by default, render images in emails to not leak the read state. The privacy filter failed to filter images with a `background-image` CSS attribute. Note that the images were still passed through the Nextcloud image proxy, and thus there was no IP leakage. The issue was patched in version 1.9.6 and 1.10.0. No workarounds are known to exist.

Nextcloud Richdocuments in an open source self hosted online office. Nextcloud uses the WOPI ("Web Application Open Platform Interface") protocol to communicate with the Collabora Editor, the communication between these two services was not protected by a credentials or IP check. Whilst this does not result in gaining access to data that the user has not yet access to, it can result in a bypass of any enforced watermark on documents as described on the [Nextcloud Virtual Data Room](https://nextcloud.com/virtual-data-room/) website and [our documentation](https://portal.nextcloud.com/article/nextcloud-and-virtual-data-room-configuration-59.html). The Nextcloud Richdocuments releases 3.8.3 and 4.2.0 add an additional admin settings for an allowlist of IP addresses that can access the WOPI API. We recommend upgrading and configuring the allowlist to a list of Collabora servers. There is no known workaround. Note that this primarily results a bypass of any configured watermark or download protection using File Access Control. If you do not require or rely on these as a security feature no immediate action is required on your end.

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 25.0.0 and prior to versions 25.0.11, 26.0.6, and 27.1.0 of Nextcloud Server and starting in version 22.0.0 and prior to versions 22.2.10.16, 23.0.12.11, 24.0.12.7, 25.0.11, 26.0.6, and 27.1.0 of Nextcloud Enterprise Server, an attacker could enable and disable the birthday calendar for any user on the same server. Nextcloud Server 25.0.11, 26.0.6, and 27.1.0 and Nextcloud Enterprise Server 22.2.10.16, 23.0.12.11, 24.0.12.7, 25.0.11, 26.0.6, and 27.1.0 contain patches for this issue. No known workarounds are available.

A missing check in Nextcloud Server 14.0.3 could give recipient the possibility to extend the expiration date of a share they received.

A missing file type check in Nextcloud Contacts 3.2.0 allowed a malicious user to upload any file as avatars.

Nextcloud mail is a Mail app for the Nextcloud home server product. Versions of Nextcloud mail prior to 1.12.2 were found to be missing user account ownership checks when performing tasks related to mail attachments. Attachments may have been exposed to incorrect system users. It is recommended that the Nextcloud Mail app is upgraded to 1.12.2. There are no known workarounds for this issue. ### Workarounds No workaround available ### References * [Pull request](https://github.com/nextcloud/mail/pull/6600) * [HackerOne](https://hackerone.com/reports/1579820) ### For more information If you have any questions or comments about this advisory: * Create a post in [nextcloud/security-advisories](https://github.com/nextcloud/security-advisories/discussions) * Customers: Open a support ticket at [support.nextcloud.com](https://support.nextcloud.com)

Nextcloud Server is a self hosted personal cloud system. An attacker with read-only access to a file is able to restore older versions of a document when the files_versions app is enabled. It is recommended that the Nextcloud Server is upgraded to 26.0.12, 27.1.7 or 28.0.3 and that the Nextcloud Enterprise Server is upgraded to 23.0.12.16, 24.0.12.12, 25.0.13.6, 26.0.12, 27.1.7 or 28.0.3.

Nextcloud Deck is a Kanban-style project & personal management tool for Nextcloud. In versions prior to 1.4.8, 1.5.6, and 1.6.1, an authenticated user can move stacks with cards from their own board to a board of another user. The Nextcloud Deck app contains a patch for this issue in versions 1.4.8, 1.5.6, and 1.6.1. There are no known currently-known workarounds available.

Nextcloud Server is the file server software for Nextcloud, a self-hosted productivity platform. Prior to versions 20.0.14.4, 21.0.8, 22.2.4, and 23.0.1, it is possible to create files and folders that have leading and trailing \n, \r, \t, and \v characters. The server rejects files and folders that have these characters in the middle of their names, so this might be an opportunity for injection. This issue is fixed in versions 20.0.14.4, 21.0.8, 22.2.4, and 23.0.1. There are currently no known workarounds.

Nextcloud Talk is a video and audio conferencing app for Nextcloud. In versions prior to 13.0.5 and 14.0.0, a call moderator can indirectly enable user webcams by granting permissions, if they were enabled before removing the permissions. A patch is available in versions 13.0.5 and 14.0.0. There are currently no known workarounds.

Nextcloud Talk is a video and audio conferencing app for Nextcloud, a self-hosted productivity platform. Prior to versions 11.3.4, 12.2.2, and 13.0.0, when sharing a Deck card in conversation, the metaData can be manipulated so users can be tricked into opening arbitrary URLs. This issue is fixed in versions 11.3.4, 12.2.2, and 13.0.0. There are currently no known workarounds.

Dangling remote share attempts in Nextcloud 16 allow a DNS pollution when running long.

Improper permissions preservation in Nextcloud Server 16.0.1 causes sharees to be able to reshare with write permissions when sharing the mount point of a share they received, as a public link.

Nextcloud Server before 9.0.55 and 10.0.2 suffers from a bypass in the quota limitation. Due to not properly sanitizing values provided by the `OC-Total-Length` HTTP header an authenticated adversary may be able to exceed their configured user quota. Thus using more space than allowed by the administrator.

Nextcloud Server before 9.0.54 and 10.0.0 suffers from an improper authorization check on removing shares. The Sharing Backend as implemented in Nextcloud does differentiate between shares to users and groups. In case of a received group share, users should be able to unshare the file to themselves but not to the whole group. The previous API implementation simply unshared the file to all users in the group.

Nextcloud Mail before 1.9.5 suffers from improper access control due to a missing permission check allowing other authenticated users to create mail aliases for other users.

Improper Input Validation in Nextcloud Server 15.0.7 allows group admins to create users with IDs of system folders.

Nextcloud guests app is a utility to create guest users which can only see files shared with them. In affected versions users could change the allowed list of apps, allowing them to use apps that were not intended to be used. It is recommended that the Guests app is upgraded to 2.4.1, 2.5.1 or 3.0.1. There are no known workarounds for this vulnerability.

Improper access control in Nextcloud Deck 1.0.0 allowed an attacker to inject tasks into other users decks.

Nextcould talk android is the android OS implementation of the nextcloud talk chat system. In affected versions the receiver is not protected by broadcastPermission allowing malicious apps to monitor communication. It is recommended that the Nextcloud Talk Android is upgraded to 14.1.0. There are no known workarounds for this issue.

Improper access control in Groupfolders app 4.0.3 allowed to delete hidden directories when when renaming an accessible item to the same name.

Nextcloud server is an open source, personal cloud implementation. In versions from 24.0.0 and before 24.0.9 a user could escalate their permissions to delete files they were not supposed to deletable but only viewed or downloaded. This issue has been addressed andit is recommended that the Nextcloud Server is upgraded to 24.0.9. There are no known workarounds for this vulnerability.

Nextcloud office/richdocuments is an office suit for the nextcloud server platform. In affected versions the Collabora integration can be tricked to provide access to any file without proper permission validation. As a result any user with access to Collabora can obtain the content of other users files. It is recommended that the Nextcloud Office App (Collabora Integration) is updated to 7.0.2 (Nextcloud 25), 6.3.2 (Nextcloud 24), 5.0.10 (Nextcloud 23), 4.2.9 (Nextcloud 21-22), or 3.8.7 (Nextcloud 15-20). There are no known workarounds for this issue.

Nextcloud Android app is the Android client for Nextcloud, a self-hosted productivity platform. In versions prior to 3.19.0, any application with notification permission can access contacts if Nextcloud has access to Contacts without applying for the Contacts permission itself. Version 3.19.0 contains a fix for this issue. There are currently no known workarounds.

Nextcloud Server before 9.0.55 and 10.0.2 suffers from a permission increase on re-sharing via OCS API issue. A permission related issue within the OCS sharing API allowed an authenticated adversary to reshare shared files with an increasing permission set. This may allow an attacker to edit files in a share despite having only a 'read' permission set. Note that this only affects folders and files that the adversary has at least read-only permissions for.

An issue was discovered in Mattermost Server before 3.3.0. An attacker could use the WebSocket feature to send pop-up messages to users or change a post's appearance.

An issue was discovered in Mattermost Server before 3.0.0. It has a superfluous API in which the System Admin can change the account name and e-mail address of an LDAP account.

Bhima version 1.27.0 allows an authenticated attacker with regular user permissions to update arbitrary user session data such as username, email and password. This is possible because the application is vulnerable to IDOR, it does not correctly validate user permissions with respect to certain actions that can be performed by the user.

A flaw was found in Samba. An incomplete access check on dnsHostName allows authenticated but otherwise unprivileged users to delete this attribute from any object in the directory.

The orbisius-child-theme-creator plugin before 1.2.8 for WordPress has incorrect access control for file modification via the wp-admin/admin-ajax.php?action=orbisius_ctc_theme_editor_ajax&sub_cmd=save_file theme_1, theme_1_file, or theme_1_file_contents parameter.

Insecure permissions in Chocolatey PHP package v8.1.12 and below grants all users in the Authenticated Users group write privileges for the subfolder C:\tools\php81 and all files located in that folder.

An issue was discovered in Mattermost Server before 5.1. It allows attackers to bypass intended access restrictions (for group-message channel creation) via the Group message slash command.

Insecure permissions in Chocolatey Ruby package v3.1.2.1 and below grants all users in the Authenticated Users group write privileges for the path C:\tools\ruby31 and all files located in that folder.

An issue was discovered in Mattermost Server before 5.1, 5.0.2, and 4.10.2. An attacker could use the invite_people slash command to invite a non-permitted user.

A vulnerability, which was classified as problematic, was found in Code4Berry Decoration Management System 1.0. This affects an unknown part of the file /decoration/admin/user_permission.php of the component User Permission Handler. The manipulation leads to permission issues. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

cPanel before 71.9980.37 allows attackers to make API calls that bypass the images feature restriction (SEC-430).

Insecure permissions in Chocolatey Azure-Pipelines-Agent package v2.211.1 and below grants all users in the Authenticated Users group write privileges for the subfolder C:\agent and all files located in that folder.

cPanel before 71.9980.37 allows attackers to make API calls that bypass the cron feature restriction (SEC-427).

The WP 2FA – Two-factor authentication for WordPress plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 2.5.0 via the send_backup_codes_email due to missing validation on a user controlled key. This makes it possible for subscriber-level attackers to email arbitrary users on the site.

The Easy Social Feed plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on multiple AJAX functions in all versions up to, and including, 6.5.2. This makes it possible for authenticated attackers, with subscriber-level access and above, to perform unauthorized actions, such as modifying the plugin's Facebook and Instagram access tokens and updating group IDs.

A vulnerability classified as problematic has been found in PHPGurukul Online Notes Sharing System 1.0. Affected is an unknown function of the file /user/profile.php of the component Contact Information Handler. The manipulation of the argument mobilenumber leads to improper access controls. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. VDB-248742 is the identifier assigned to this vulnerability.

An issue was discovered in Mattermost Server before 5.2, 5.1.1, 5.0.3, and 4.10.3. Attackers could use multiple e-mail addresses to bypass a domain-based policy for signups.

An issue was discovered in Mattermost Server before 5.1. An attacker can bypass intended access control (for direct-message channel creation) via the Message slash command.

An issue was discovered in Mattermost Server before 4.8.1, 4.7.4, and 4.6.3. An e-mail invite accidentally included the team invite_id, which leads to unintended excessive invitation privileges.

Insecure permissions in Chocolatey Cmder package v1.3.20 and below grants all users in the Authenticated Users group write privileges for the path C:\tools\Cmder and all files located in that folder.

An issue was discovered in Mattermost Server before 5.1. Non-members of a channel could use the Channel PATCH API to modify that channel.