CVE-2024-38518Network attack vector

Moderator privilege escalation via signed join parameters

Published Jun 28, 2024 · Updated Aug 2, 2024

Improper access control in BigBlueButton allows remote authenticated users with viewer join links to gain moderator privileges. The bbb-web join API signs attacker-supplied additional parameters from a valid viewer link without excluding role=moderator, so the generated URL carries the elevated role. A valid join link and meeting access are required; the resulting moderator session exposes meeting content and permits moderator actions.

CVSS severity4.6
Medium
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in BigBlueButton allows remote authenticated users with viewer join links to gain moderator privileges. The bbb-web join API signs attacker-supplied additional parameters from a valid viewer link without excluding role=moderator, so the generated URL carries the elevated role. A valid join link and meeting access are required; the resulting moderator session exposes meeting content and permits moderator actions.

The record

CVE
CVE-2024-38518
Published
Jun 28, 2024
Updated
Aug 2, 2024
Vendor
BigBlueButton Inc.
Product
BigBlueButton
Classifications
CWE-284, T1068
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 28, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.6.18
  2. Affected versionversion=>= 2.7.0, < 2.7.8
  3. Affected versionversion=>= 2.8.0, < 3.0.0-alpha.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

BigBlueButton Inc. · BigBlueButtonversion=< 2.6.18; version=>= 2.7.0, < 2.7.8; version=>= 2.8.0, < 3.0.0-alpha.7

Published CVSS scores

4.6GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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