BigBlueButton 2.3 / 2.4.7 Cross Site Scripting

BigBlueButton versions 2.3, prior to 2.4.8, and prior to 2.5.0 suffer from a persistent cross site scripting vulnerability.

SHA-256 | c68ede95337b08934eceb60e7e3ded22f6717375681d84eac96231f4c47ee8b1

CVE-2022-31064 - Stored Cross-Site Scripting in BigBlueButton.


Exploit Title: Stored Cross-Site Scripting (XSS) in BigBlueButton

Product: BigBlueButton

Vendor: BigBlueButton

Vulnerable Versions: 2.3, <2.4.8, <2.5.0

Tested Version: 2.4.7

Advisory Publication: Jun 22, 2022

Latest Update: Jun 22, 2022

Vulnerability Type: Cross-Site Scripting [CWE-79]

CVE Reference: CVE-2022-31064

CVSS Severity: High

Impact score: 7.2

Credit: Rick Verdoes & Danny de Weille (Hackify |


BigBlueButton is an open source web conferencing system designed for online meetings and online learning. BigBlueButton is a tool used by instructors and teachers, which helps them access to Learning Management Systems, engagement tools and analytics.

Users in meetings with private chat enabled are vulnerable to a cross site scripting attack in affected versions. The attack occurs when the attacker (with a XSS payload in the name) starts a chat. in the victim's client the JavaScript will be executed. This issue has been addressed in version 2.4.8 and 2.5.0. There are no known workarounds for this issue.

III. Proof of Concept
<img x onerror=alert()>

IV. References
Security advisory
Patched on BigBlueButton 2.5 (
Patched on BigBlueButton 2.4 (

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