Fortinet Discovers Nextcloud Cross-Site Scripting Vulnerability

Summary

Fortinet's FortiGuard Labs has discovered a stored Cross-Site Scripting (XSS) vulnerability in Nextcloud Filename.


Nextcloud offers the industry-leading, on-premises content collaboration platform.


A stored XSS vulnerability has been discovered in Nextcloud 19.0.0 and earlier versions. It is caused by inadequate filtering on the filename.

Solutions

FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:

Nextcloud.NotificationShow.XSS
Released Jun 17, 2020

Users should apply the solution provided by Nextcloud.

Timeline

Fortinet reported the vulnerability to Nextcloud on June 12, 2020.

Nextcloud confirmed the vulnerability on June 12, 2020.

Nextcloud patched the vulnerability on February 10, 2021.

Acknowledgement

This vulnerability was discovered by Zhouyuan Yang of Fortinet's FortiGuard Labs.

IPS Subscription

Fortinet customers who subscribe to Fortinet's intrusion prevention (IPS) service should be protected against this vulnerability with the appropriate configuration parameters in place. Fortinet's IPS service is one component of FortiGuard Subscription Services, which also offer comprehensive solutions such as antivirus, Web content filtering and antispam capabilities. These services enable protection against threats on both application and network layers. FortiGuard Services are continuously updated by FortiGuard Labs, which enables Fortinet to deliver a combination of multi-layered security intelligence and true zero-day protection from new and emerging threats. These updates are delivered to all FortiGate, FortiMail and FortiClient products. Fortinet strictly follows responsible disclosure guidelines to ensure optimum protection during a threat's lifecycle.