Impact
The Nextcloud Contacts 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.
Patches
It is recommended that the Nextcloud Contacts application is upgraded to 4.0.3.
Workarounds
Use a browser that has support for Content-Security-Policy. You can find a list of supported browsers on caniuse.com. A notable exemption is Internet Explorer which does not support CSP properly.
References
For more information
If you have any questions or comments about this advisory:
Impact
The Nextcloud Contacts 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.
Patches
It is recommended that the Nextcloud Contacts application is upgraded to 4.0.3.
Workarounds
Use a browser that has support for Content-Security-Policy. You can find a list of supported browsers on caniuse.com. A notable exemption is Internet Explorer which does not support CSP properly.
References
For more information
If you have any questions or comments about this advisory: