CVE-2021-29438: nextcloud nextcloud-dialogs Cross-site Scripting

Vulnerability summary

CVE-2021-29438 is a medium (CVSS 5.4) Cross-site Scripting vulnerability in nextcloud nextcloud-dialogs. EPSS estimates a 0.70% chance of exploitation in the next 30 days, higher than 52.3% of scored vulnerabilities.

Timeline

1. 13-04-2021
   PublishedVulnerability first disclosed.
2. 03-08-2024
   Last modifiedVulnerability information updated.

Description

The Nextcloud dialogs library (npm package @nextcloud/dialogs) before 3.1.2 insufficiently escaped text input passed to a toast. If your application displays toasts with user-supplied input, this could lead to a XSS vulnerability. The vulnerability has been patched in version 3.1.2 If you need to display HTML in the toast, explicitly pass the `options.isHTML` config flag.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
• CWE-80Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.