Vulnerabilities (CVE)

Filtered by vendor Nextcloud Subscribe
CVE Vendors Products Updated CVSS v2 CVSS v3
CVE-2020-8223 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud Server 2022-01-01 3.5 LOW 6.5 MEDIUM
A logic error in Nextcloud Server 19.0.0 caused a privilege escalation allowing malicious users to reshare with higher permissions than they got assigned themselves.
CVE-2020-8296 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud Server 2022-01-01 4.6 MEDIUM 6.7 MEDIUM
Nextcloud Server prior to 20.0.0 stores passwords in a recoverable format even when external storage is not configured.
CVE-2021-22877 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud 2022-01-01 5.5 MEDIUM 6.5 MEDIUM
A missing user check in Nextcloud prior to 20.0.6 inadvertently populates a user's own credentials for other users external storage configuration when not already configured yet.
CVE-2021-22878 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud Server 2022-01-01 3.5 LOW 4.8 MEDIUM
Nextcloud Server prior to 20.0.6 is vulnerable to reflected cross-site scripting (XSS) due to lack of sanitization in `OC.Notification.show`.
CVE-2020-8118 3 Nextcloud, Novell, Opensuse 3 Nextcloud Server, Suse Linux Enterprise Server, Backports Sle 2021-12-22 4.0 MEDIUM 5.0 MEDIUM
An authenticated server-side request forgery in Nextcloud server 16.0.1 allowed to detect local and remote services when adding a new subscription in the calendar application.
CVE-2021-32728 2 Debian, Nextcloud 2 Debian Linux, Nextcloud 2021-12-16 4.0 MEDIUM 6.5 MEDIUM
The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading.
CVE-2021-22895 2 Debian, Nextcloud 2 Debian Linux, Desktop 2021-12-02 4.3 MEDIUM 5.9 MEDIUM
Nextcloud Desktop Client before 3.3.1 is vulnerable to improper certificate validation due to lack of SSL certificate verification when using the "Register with a Provider" flow.
CVE-2021-41256 1 Nextcloud 1 News 2021-12-02 5.8 MEDIUM 7.1 HIGH
nextcloud news-android is an Android client for the Nextcloud news/feed reader app. In affected versions the Nextcloud News for Android app has a security issue by which a malicious application installed on the same device can send it an arbitrary Intent that gets reflected back, unintentionally giving read and write access to non-exported Content Providers in Nextcloud News for Android. Users should upgrade to version 0.9.9.63 or higher as soon as possible.
CVE-2021-39222 1 Nextcloud 1 Talk 2021-11-17 4.3 MEDIUM 6.1 MEDIUM
Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Talk application was vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. For exploitation, a user would need to right-click on a malicious file and open the file in a new tab. Due the strict Content-Security-Policy shipped with Nextcloud, this issue is not exploitable on modern browsers supporting Content-Security-Policy. It is recommended that the Nextcloud Talk application is upgraded to patched versions 10.0.7, 10.1.4, 11.1.2, 11.2.0 or 12.0.0. As a workaround, use a browser that has support for Content-Security-Policy.
CVE-2019-5452 1 Nextcloud 1 Nextcloud 2021-11-03 2.1 LOW 2.4 LOW
Bypass lock protection in the Nextcloud Android app prior to version 3.6.2 causes leaking of thumbnails when requesting the Android content provider although the lock protection was not solved.
CVE-2019-5451 1 Nextcloud 1 Nextcloud Server 2021-11-03 2.1 LOW 4.6 MEDIUM
Bypass lock protection in the Nextcloud Android app prior to version 3.6.1 allows accessing the files when repeatedly opening and closing the app in a very short time.
CVE-2019-5450 1 Nextcloud 1 Nextcloud 2021-11-03 4.6 MEDIUM 6.8 MEDIUM
Improper sanitization of HTML in directory names in the Nextcloud Android app prior to version 3.7.0 allowed to style the directory name in the header bar when using basic HTML.
CVE-2019-15623 3 Nextcloud, Opensuse, Suse 3 Nextcloud Server, Backports Sle, Package Hub 2021-10-29 5.0 MEDIUM 5.3 MEDIUM
Exposure of Private Information in Nextcloud Server 16.0.1 causes the server to send it's domain and user IDs to the Nextcloud Lookup Server without any further data when the Lookup server is disabled.
CVE-2021-41179 1 Nextcloud 1 Server 2021-10-29 4.0 MEDIUM 6.5 MEDIUM
Nextcloud is an open-source, self-hosted productivity platform. Prior to Nextcloud Server versions 20.0.13, 21.0.5, and 22.2.0, the Two-Factor Authentication wasn't enforced for pages marked as public. Any page marked as `@PublicPage` could thus be accessed with a valid user session that isn't authenticated. This particularly affects the Nextcloud Talk application, as this could be leveraged to gain access to any private chat channel without going through the Two-Factor flow. It is recommended that the Nextcloud Server be upgraded to 20.0.13, 21.0.5 or 22.2.0. There are no known workarounds aside from upgrading.
CVE-2021-39224 1 Nextcloud 1 Officeonline 2021-10-29 5.0 MEDIUM 5.3 MEDIUM
Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud OfficeOnline application prior to version 1.1.1 returned verbatim exception messages to the user. This could result in a full path disclosure on shared files. (e.g. an attacker could see that the file `shared.txt` is located within `/files/$username/Myfolder/Mysubfolder/shared.txt`). It is recommended that the OfficeOnline application is upgraded to 1.1.1. As a workaround, one may disable the OfficeOnline application in the app settings.
CVE-2021-39223 1 Nextcloud 1 Richdocuments 2021-10-29 5.0 MEDIUM 5.3 MEDIUM
Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Richdocuments application prior to versions 3.8.6 and 4.2.3 returned verbatim exception messages to the user. This could result in a full path disclosure on shared files. (e.g. an attacker could see that the file `shared.txt` is located within `/files/$username/Myfolder/Mysubfolder/shared.txt`). It is recommended that the Richdocuments application is upgraded to 3.8.6 or 4.2.3. As a workaround, disable the Richdocuments application in the app settings.
CVE-2021-41177 1 Nextcloud 1 Nextcloud Server 2021-10-28 5.5 MEDIUM 8.1 HIGH
Nextcloud is an open-source, self-hosted productivity platform. Prior to versions 20.0.13, 21.0.5, and 22.2.0, Nextcloud Server did not implement a database backend for rate-limiting purposes. Any component of Nextcloud using rate-limits (as as `AnonRateThrottle` or `UserRateThrottle`) was thus not rate limited on instances not having a memory cache backend configured. In the case of a default installation, this would notably include the rate-limits on the two factor codes. It is recommended that the Nextcloud Server be upgraded to 20.0.13, 21.0.5, or 22.2.0. As a workaround, enable a memory cache backend in `config.php`.
CVE-2021-39221 1 Nextcloud 1 Contacts 2021-10-27 3.5 LOW 5.4 MEDIUM
Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Contacts application prior to version 4.0.3 was vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. For exploitation, a user would need to right-click on a malicious file and open the file in a new tab. Due the strict Content-Security-Policy shipped with Nextcloud, this issue is not exploitable on modern browsers supporting Content-Security-Policy. It is recommended that the Nextcloud Contacts application is upgraded to 4.0.3. As a workaround, one may use a browser that has support for Content-Security-Policy.
CVE-2021-39220 1 Nextcloud 1 Mail 2021-10-27 3.5 LOW 3.5 LOW
Nextcloud is an open-source, self-hosted productivity platform The Nextcloud Mail application prior to versions 1.10.4 and 1.11.0 does by default not render images in emails to not leak the read state or user IP. The privacy filter failed to filter images with a relative protocol. It is recommended that the Nextcloud Mail application is upgraded to 1.10.4 or 1.11.0. There are no known workarounds aside from upgrading.
CVE-2020-8229 1 Nextcloud 1 Nextcloud 2021-09-23 4.9 MEDIUM 5.5 MEDIUM
A memory leak in the OCUtil.dll library used by Nextcloud Desktop Client 2.6.4 can lead to a DoS against the host system.
CVE-2021-22915 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud Server 2021-09-20 5.0 MEDIUM 9.8 CRITICAL
Nextcloud server before 19.0.11, 20.0.10, 21.0.2 is vulnerable to brute force attacks due to lack of inclusion of IPv6 subnets in rate-limiting considerations. This could potentially result in an attacker bypassing rate-limit controls such as the Nextcloud brute-force protection.
CVE-2021-32705 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud Server 2021-09-20 5.0 MEDIUM 7.5 HIGH
Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.13, 20.011, and 21.0.3, there was a lack of ratelimiting on the public DAV endpoint. This may have allowed an attacker to enumerate potentially valid share tokens or credentials. The issue was fixed in versions 19.0.13, 20.0.11, and 21.0.3. There are no known workarounds.
CVE-2021-32703 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud Server 2021-09-20 5.0 MEDIUM 5.3 MEDIUM
Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.13, 20.011, and 21.0.3, there was a lack of ratelimiting on the shareinfo endpoint. This may have allowed an attacker to enumerate potentially valid share tokens. The issue was fixed in versions 19.0.13, 20.0.11, and 21.0.3. There are no known workarounds.
CVE-2021-32678 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud Server 2021-09-20 5.0 MEDIUM 5.3 MEDIUM
Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.13, 20.0.11, and 21.0.3, ratelimits are not applied to OCS API responses. This affects any OCS API controller (`OCSController`) using the `@BruteForceProtection` annotation. Risk depends on the installed applications on the Nextcloud Server, but could range from bypassing authentication ratelimits or spamming other Nextcloud users. The vulnerability is patched in versions 19.0.13, 20.0.11, and 21.0.3. No workarounds aside from upgrading are known to exist.
CVE-2021-32688 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud Server 2021-09-20 7.5 HIGH 8.8 HIGH
Nextcloud Server is a Nextcloud package that handles data storage. Nextcloud Server supports application specific tokens for authentication purposes. These tokens are supposed to be granted to a specific applications (e.g. DAV sync clients), and can also be configured by the user to not have any filesystem access. Due to a lacking permission check, the tokens were able to change their own permissions in versions prior to 19.0.13, 20.0.11, and 21.0.3. Thus fileystem limited tokens were able to grant themselves access to the filesystem. The issue is patched in versions 19.0.13, 20.0.11, and 21.0.3. There are no known workarounds aside from upgrading.
CVE-2021-32680 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud Server 2021-09-20 2.1 LOW 3.3 LOW
Nextcloud Server is a Nextcloud package that handles data storage. In versions priot to 19.0.13, 20.0.11, and 21.0.3, Nextcloud Server audit logging functionality wasn't properly logging events for the unsetting of a share expiration date. This event is supposed to be logged. This issue is patched in versions 19.0.13, 20.0.11, and 21.0.3.
CVE-2021-32679 2 Fedoraproject, Nextcloud 2 Fedora, Nextcloud Server 2021-09-20 6.8 MEDIUM 8.8 HIGH
Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.13, 20.0.11, and 21.0.3, filenames where not escaped by default in controllers using `DownloadResponse`. When a user-supplied filename was passed unsanitized into a `DownloadResponse`, this could be used to trick users into downloading malicious files with a benign file extension. This would show in UI behaviours where Nextcloud applications would display a benign file extension (e.g. JPEG), but the file will actually be downloaded with an executable file extension. The vulnerability is patched in versions 19.0.13, 20.0.11, and 21.0.3. Administrators of Nextcloud instances do not have a workaround available, but developers of Nextcloud apps may manually escape the file name before passing it into `DownloadResponse`.
CVE-2021-32766 1 Nextcloud 1 Nextcloud 2021-09-14 5.0 MEDIUM 5.3 MEDIUM
Nextcloud Text is an open source plaintext editing application which ships with the nextcloud server. In affected versions the Nextcloud Text application returned different error messages depending on whether a folder existed in a public link share. This is problematic in case the public link share has been created with "Upload Only" privileges. (aka "File Drop"). A link share recipient is not expected to see which folders or files exist in a "File Drop" share. Using this vulnerability an attacker is able to enumerate folders in such a share. Exploitation requires that the attacker has access to a valid affected "File Drop" link share. It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.0.1. Users who are unable to upgrade are advised to disable the Nextcloud Text application in the app settings.
CVE-2021-37628 1 Nextcloud 1 Richdocuments 2021-09-14 5.0 MEDIUM 7.5 HIGH
Nextcloud Richdocuments is an open source collaborative office suite. In affected versions the File Drop features ("Upload Only" public link shares in Nextcloud) can be bypassed using the Nextcloud Richdocuments app. An attacker was able to read arbitrary files in such a share. It is recommended that the Nextcloud Richdocuments is upgraded to 3.8.4 or 4.2.1. If upgrading is not possible then it is recommended to disable the Richdocuments application.
CVE-2021-32802 1 Nextcloud 1 Nextcloud 2021-09-14 10.0 HIGH 9.8 CRITICAL
Nextcloud server is an open source, self hosted personal cloud. Nextcloud supports rendering image previews for user provided file content. For some image types, the Nextcloud server was invoking a third-party library that wasn't suited for untrusted user-supplied content. There are several security concerns with passing user-generated content to this library, such as Server-Side-Request-Forgery, file disclosure or potentially executing code on the system. The risk depends on your system configuration and the installed library version. It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.1.0. These versions do not use this library anymore. As a workaround users may disable previews by setting `enable_previews` to `false` in `config.php`.
CVE-2021-32801 1 Nextcloud 1 Nextcloud 2021-09-14 2.1 LOW 5.5 MEDIUM
Nextcloud server is an open source, self hosted personal cloud. In affected versions logging of exceptions may have resulted in logging potentially sensitive key material for the Nextcloud Encryption-at-Rest functionality. It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.1.0. If upgrading is not an option users are advised to disable system logging to resolve this issue until such time that an upgrade can be performed Note that ff you do not use the Encryption-at-Rest functionality of Nextcloud you are not affected by this bug.
CVE-2021-32800 1 Nextcloud 1 Nextcloud 2021-09-14 6.4 MEDIUM 8.1 HIGH
Nextcloud server is an open source, self hosted personal cloud. In affected versions an attacker is able to bypass Two Factor Authentication in Nextcloud. Thus knowledge of a password, or access to a WebAuthN trusted device of a user was sufficient to gain access to an account. It is recommended that the Nextcloud Server is upgraded to 20.0.12, 21.0.4 or 22.1.0. There are no workaround for this vulnerability.
CVE-2021-37631 1 Nextcloud 1 Deck 2021-09-14 4.0 MEDIUM 6.5 MEDIUM
Deck is an open source kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. In affected versions the Deck application didn't properly check membership of users in a Circle. This allowed other users in the instance to gain access to boards that have been shared with a Circle, even if the user was not a member of the circle. It is recommended that Nextcloud Deck is upgraded to 1.5.1, 1.4.4 or 1.2.9. If you are unable to update it is advised to disable the Deck plugin.
CVE-2021-37630 1 Nextcloud 1 Circles 2021-09-14 4.0 MEDIUM 6.5 MEDIUM
Nextcloud Circles is an open source social network built for the nextcloud ecosystem. In affected versions the Nextcloud Circles application allowed any user to join any "Secret Circle" without approval by the Circle owner leaking private information. It is recommended that Nextcloud Circles is upgraded to 0.19.15, 0.20.11 or 0.21.4. There are no workarounds for this issue.
CVE-2021-37629 1 Nextcloud 1 Richdocuments 2021-09-14 5.0 MEDIUM 5.3 MEDIUM
Nextcloud Richdocuments is an open source collaborative office suite. In affected versions there is a lack of rate limiting on the Richdocuments OCS endpoint. This may have allowed an attacker to enumerate potentially valid share tokens. It is recommended that the Nextcloud Richdocuments app is upgraded to either 3.8.4 or 4.2.1 to resolve. For users unable to upgrade it is recommended that the Richdocuments application be disabled.
CVE-2021-32782 1 Nextcloud 1 Circles 2021-09-10 3.5 LOW 5.4 MEDIUM
Nextcloud Circles is an open source social network built for the nextcloud ecosystem. In affected versions the Nextcloud Circles application is vulnerable to a stored Cross-Site Scripting (XSS) vulnerability. Due the strict Content-Security-Policy shipped with Nextcloud, this issue is not exploitable on modern browsers supporting Content-Security-Policy. It is recommended that the Nextcloud Circles application is upgraded to 0.21.3, 0.20.10 or 0.19.14 to resolve this issue. As a workaround users may use a browser that has support for Content-Security-Policy. A notable exemption is Internet Explorer which does not support CSP properly.
CVE-2021-37617 1 Nextcloud 1 Desktop 2021-08-24 4.4 MEDIUM 7.3 HIGH
The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. The Nextcloud Desktop Client invokes its uninstaller script when being installed to make sure there are no remnants of previous installations. In versions 3.0.3 through 3.2.4, the Client searches the `Uninstall.exe` file in a folder that can be written by regular users. This could lead to a case where a malicious user creates a malicious `Uninstall.exe`, which would be executed with administrative privileges on the Nextcloud Desktop Client installation. This issue is fixed in Nextcloud Desktop Client version 3.3.0. As a workaround, do not allow untrusted users to create content in the `C:\` system folder and verify that there is no malicious `C:\Uninstall.exe` file on the system.
CVE-2021-32748 1 Nextcloud 1 Richdocuments 2021-08-09 4.0 MEDIUM 4.3 MEDIUM
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.
CVE-2021-32694 1 Nextcloud 1 Nextcloud 2021-06-24 4.3 MEDIUM 5.5 MEDIUM
Nextcloud Android app is the Android client for Nextcloud. In versions prior to 3.15.1, a malicious application on the same device is possible to crash the Nextcloud Android Client due to an uncaught exception. The vulnerability is patched in version 3.15.1.
CVE-2021-32676 1 Nextcloud 1 Talk 2021-06-23 4.0 MEDIUM 6.5 MEDIUM
Nextcloud Talk is a fully on-premises audio/video and chat communication service. Password protected shared chats in Talk before version 9.0.10, 10.0.8 and 11.2.2 did not rotate the session cookie after a successful authentication event. It is recommended that the Nextcloud Talk App is upgraded to 9.0.10, 10.0.8 or 11.2.2. No workarounds for this vulnerability are known to exist.
CVE-2021-32695 1 Nextcloud 1 Nextcloud 2021-06-23 4.3 MEDIUM 3.3 LOW
Nextcloud Android app is the Android client for Nextcloud. In versions prior to 3.16.1, a malicious app on the same device could have gotten access to the shared preferences of the Nextcloud Android application. This required user-interaction as a victim had to initiate the sharing flow and choose the malicious app. The shared preferences contain some limited private data such as push tokens and the account name. The vulnerability is patched in version 3.16.1.
CVE-2021-22913 1 Nextcloud 1 Deck 2021-06-23 4.3 MEDIUM 6.5 MEDIUM
Nextcloud Deck before 1.2.7, 1.4.1 suffers from an information disclosure vulnerability when searches for sharees utilize the lookup server by default instead of only the local Nextcloud server unless a global search has been explicitly chosen by the user.
CVE-2021-22905 1 Nextcloud 1 Nextcloud 2021-06-22 4.3 MEDIUM 6.5 MEDIUM
Nextcloud Android App (com.nextcloud.client) before v3.16.0 is vulnerable to information disclosure due to searches for sharees being performed by default on the lookup server instead of only using the local Nextcloud server unless a global search has been explicitly chosen by the user.
CVE-2021-22906 1 Nextcloud 1 End-to-end Encryption 2021-06-22 4.0 MEDIUM 6.5 MEDIUM
Nextcloud End-to-End Encryption before 1.5.3, 1.6.3 and 1.7.1 suffers from a denial of service vulnerability due to permitting any authenticated users to lock files of other users.
CVE-2021-22912 1 Nextcloud 1 Nextcloud 2021-06-22 4.3 MEDIUM 6.5 MEDIUM
Nextcloud iOS before 3.4.2 suffers from an information disclosure vulnerability when searches for sharees utilize the lookup server by default instead of only on the local Nextcloud server unless a global search has been explicitly chosen by the user.
CVE-2021-22896 1 Nextcloud 1 Nextcloud 2021-06-22 4.0 MEDIUM 4.3 MEDIUM
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.
CVE-2021-32658 1 Nextcloud 1 Nextcloud 2021-06-21 2.1 LOW 4.6 MEDIUM
Nextcloud Android is the Android client for the Nextcloud open source home cloud system. Due to a timeout issue the Android client may not properly clean all sensitive data on account removal. This could include sensitive key material such as the End-to-End encryption keys. It is recommended that the Nextcloud Android App is upgraded to 3.16.1
CVE-2021-32653 1 Nextcloud 1 Nextcloud Server 2021-06-14 4.0 MEDIUM 2.7 LOW
Nextcloud Server is a Nextcloud package that handles data storage. Nextcloud Server versions prior to 19.0.11, 20.0.10, or 21.0.2 send user IDs to the lookup server even if the user has no fields set to published. The vulnerability is patched in versions 19.0.11, 20.0.10, and 21.0.2; no workarounds outside the updates are known to exist.
CVE-2021-32652 1 Nextcloud 1 Nextcloud Mail 2021-06-14 4.0 MEDIUM 4.3 MEDIUM
Nextcloud Mail is a mail app for the Nextcloud platform. A missing permission check in Nextcloud Mail before 1.4.3 and 1.8.2 allows another authenticated users to access mail metadata of other users. Versions 1.4.3 and 1.8.2 contain patches for this vulnerability; no workarounds other than the patches are known to exist.
CVE-2021-32654 1 Nextcloud 1 Nextcloud Server 2021-06-14 6.4 MEDIUM 9.1 CRITICAL
Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.11, 20.0.10, and 21.0.2, an attacker is able to receive write/read privileges on any Federated File Share. Since public links can be added as federated file share, this can also be exploited on any public link. Users can upgrade to patched versions (19.0.11, 20.0.10 or 21.0.2) or, as a workaround, disable federated file sharing.