How severe is CVE-2021-4143?

CVE-2021-4143 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-4143 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-4143?

CVE-2021-4143 affects Bigbluebutton. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-4143?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-4143 published?

CVE-2021-4143 was published on 2022-01-19 and last updated on 2026-06-17.

CVE-2021-4143

CVE-2021-4143 is a medium-severity vulnerability in Bigbluebutton with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Bigbluebutton
Published: 2022-01-19
Last modified: 2026-06-17

Description

Cross-site Scripting (XSS) - Generic in GitHub repository bigbluebutton/bigbluebutton prior to 2.4.0.

Frequently asked questions

What is CVE-2021-4143?: Cross-site Scripting (XSS) - Generic in GitHub repository bigbluebutton/bigbluebutton prior to 2.4.0.
How severe is CVE-2021-4143?: CVE-2021-4143 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-4143 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-4143?: CVE-2021-4143 affects Bigbluebutton. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-4143?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-4143 published?: CVE-2021-4143 was published on 2022-01-19 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:*

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