CVE-2022-29169Network attack vector

Service interruption via User-Agent regex backtracking

Published Jun 1, 2022 · Updated Apr 23, 2025

Regular expression denial of service in affected BigBlueButton releases allows remote attackers to interrupt bbb-html5 through a User-Agent header. The /html5client/useragent handler passes the header to lookupUserAgent(), whose regex matching consumes excessive processing on a crafted SmartWatch value. No authentication or user interaction is required, and the demonstrated consequence is interruption of the bbb-html5 service rather than data access or modification.

CVSS severity7.5
High
EPSS probability1.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Regular expression denial of service in affected BigBlueButton releases allows remote attackers to interrupt bbb-html5 through a User-Agent header. The /html5client/useragent handler passes the header to lookupUserAgent(), whose regex matching consumes excessive processing on a crafted SmartWatch value. No authentication or user interaction is required, and the demonstrated consequence is interruption of the bbb-html5 service rather than data access or modification.

The record

CVE
CVE-2022-29169
Published
Jun 1, 2022
Updated
Apr 23, 2025
Vendor
BigBlueButton Inc.
Product
BigBlueButton
Classifications
CWE-1333, CWE-20, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 1, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Record 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=>= 2.2, < 2.3.19
  2. Affected versionversion=>= 2.4.0, < 2.4.7
  3. Affected versionversion=>= 2.5-alpha-1, < 2.5.0-beta.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

BigBlueButton Inc. · BigBlueButtonversion=>= 2.2, < 2.3.19; version=>= 2.4.0, < 2.4.7; version=>= 2.5-alpha-1, < 2.5.0-beta.2

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
CWE-20Improper Input Validation
T1499.004Application or System Exploitation

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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