Nextcloud: Security Vulnerabilities
Nextcloud is an open-source, self-hosted productivity platform. Prior to versions 20.0.13, 21.0.5, and 22.2.0, a file traversal vulnerability makes an attacker able to download arbitrary SVG images from the host system, including user provided files. This could also be leveraged into a XSS/phishing attack, an attacker could upload a malicious SVG file that mimics the Nextcloud login form and send a specially crafted link to victims. The XSS risk here is mitigated due to the fact that Nextcloud employs a strict Content-Security-Policy disallowing execution of arbitrary JavaScript. 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.
CVSS Score
8.8
EPSS Score
0.002
Published
2021-10-25
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.
CVSS Score
6.5
EPSS Score
0.003
Published
2021-10-25
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.
CVSS Score
3.5
EPSS Score
0.003
Published
2021-10-25
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.
CVSS Score
6.4
EPSS Score
0.003
Published
2021-10-25
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.
CVSS Score
8.1
EPSS Score
0.001
Published
2021-09-07
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.
CVSS Score
5.5
EPSS Score
0.001
Published
2021-09-07
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`.
CVSS Score
9.3
EPSS Score
0.003
Published
2021-09-07
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.
CVSS Score
5.3
EPSS Score
0.003
Published
2021-09-07
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.
CVSS Score
7.5
EPSS Score
0.004
Published
2021-09-07
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.
CVSS Score
5.3
EPSS Score
0.004
Published
2021-09-07