SB2021060601 - Cross-site scripting in Flarum

Description

This security bulletin contains information about 1 vulnerability.

1) Cross-site scripting (CVE-ID: CVE-2021-32671)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to execute arbitrary script code in a victim's browser.

The vulnerability exists due to cross-site scripting in the translation system when rendering user-supplied input as HTML DOM nodes. A remote attacker can submit malicious HTML markup to execute arbitrary script code in a victim's browser.

The issue can be triggered through certain user input fields, including the forum search box, and may allow actions to be performed on behalf of the victim.

Remediation

Install update from vendor's website.

References

• https://github.com/flarum/framework/security/advisories/GHSA-5qjq-69w6-fg57
• https://github.com/advisories/GHSA-5qjq-69w6-fg57