CVE-2022-29169 | ReDoS on endpoint html5client/useragent in BigBlueButton

BigBlueButton is an open source web conferencing system. Versions starting with 2.2 and prior to 2.3.19, 2.4.7, and 2.5.0-beta.2 are vulnerable to regular expression denial of service (ReDoS) attacks. By using specific a RegularExpression, an attacker can cause denial of service for the bbb-html5 service. The useragent library performs checking of device by parsing the input of User-Agent header and lets it go through lookupUserAgent() (alias of useragent.lookup() ). This function handles input by regexing and attackers can abuse that by providing some ReDos payload using `SmartWatch`. The maintainers removed `htmlclient/useragent` from versions 2.3.19, 2.4.7, and 2.5.0-beta.2. As a workaround, disable NginX forwarding the requests to the handler according to the directions in the GitHub Security Advisory.

Published: 2022-06-01 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-29169 is rated Moderate Risk (55/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.42%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-29169

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.65% 1.42% +0.76%
2 2025-11-25 0.62% 0.65% +0.03%
3 2025-06-10 — 0.62% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-29169

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2022-29169

Affected software / configurations for CVE-2022-29169

Vendor Product Version Raw CPE
bigbluebutton bigbluebutton >= 2.2.0, < 2.3.19 cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:*
bigbluebutton bigbluebutton >= 2.4.0, < 2.4.7 cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.5 cpe:2.3:a:bigbluebutton:bigbluebutton:2.5:alpha1:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.5 cpe:2.3:a:bigbluebutton:bigbluebutton:2.5:alpha2:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.5 cpe:2.3:a:bigbluebutton:bigbluebutton:2.5:alpha3:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.5 cpe:2.3:a:bigbluebutton:bigbluebutton:2.5:alpha4:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.5 cpe:2.3:a:bigbluebutton:bigbluebutton:2.5:alpha5:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.5 cpe:2.3:a:bigbluebutton:bigbluebutton:2.5:alpha6:*:*:*:*:*:*
bigbluebutton bigbluebutton 2.5 cpe:2.3:a:bigbluebutton:bigbluebutton:2.5:beta1:*:*:*:*:*:*

References for CVE-2022-29169

cvelogic Threat Intelligence