CVE-2022-27238
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedBigBlueButton version 2.4.7 (or earlier) is vulnerable to stored Cross-Site Scripting (XSS) in the private chat functionality. A threat actor could inject JavaScript payload in his/her username. The payload gets executed in the browser of the victim each time the attacker sends a private message to the victim or when notification about the attacker leaving room is displayed.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceBigBlueButton versions 2.4.7 and earlier contain a stored XSS vulnerability in the private chat functionality. Attackers can inject malicious JavaScript payloads into their username, which then executes in victims' browsers when the attacker sends private messages or when notifications about the attacker leaving the room are displayed.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 2.4.7CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify BigBlueButton installation versionRun the command 'bbb-conf --version' or check the BigBlueButton package version via your system's package manager (dpkg/rpm). Compare the returned version number against the affected range: versions 2.4.7 and earlier.Affected if The installed version is 2.4.7 or any version lower than 2.4.7.
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Verify private chat functionality is accessibleLog into BigBlueButton as a test user and confirm the private messaging/chat feature is available in the meeting interface. Check if users can send direct messages to other participants.Affected if Private chat is enabled and users can exchange direct messages.
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Inspect user account configurations for stored usernamesReview the user management interface or database where BigBlueButton stores user accounts. Look for any user accounts with unusual characters (such as <, >, script, javascript, onerror, onload) in their display names or usernames.Affected if Any user account contains XSS payload characters in the username field.
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Review meeting participation logs for XSS indicatorsExamine BigBlueButton meeting logs or the recordings dashboard for any usernames that contain HTML/JavaScript tags, particularly in recent activity logs where users joined or left meetings.Affected if Meeting logs show usernames with raw HTML tags or suspicious script-like patterns.
You are affected if your BigBlueButton installation is version 2.4.7 or earlier and the private chat feature is enabled, as this combination allows the stored XSS in usernames to execute when private messages are sent or room departure notifications are displayed.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataImplement strict input validation and output encoding for usernames in the chat module to neutralize XSS payloads. Consider updating BigBlueButton to a patched version if available.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-27238 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2022-27238 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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