CVE-2021-32623

Name: CVE-2021-32623
Creator: NVD / NIST
Published: 2021-06-16T00:15:07.717+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.25%

Last modified Jun 17, 2026

CVE-2021-32623 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Opencast is a free and open source solution for automated video capture and distribution. Versions of Opencast prior to 9.6 are vulnerable to the billion laughs attack, which allows an attacker to easily execute a (seemingly permanent) denial of service attack, essentially taking down Opencast using a single HTTP request. EPSS estimates a 1.25% chance of exploitation in the next 30 days.

Description

Opencast is a free and open source solution for automated video capture and distribution. Versions of Opencast prior to 9.6 are vulnerable to the billion laughs attack, which allows an attacker to easily execute a (seemingly permanent) denial of service attack, essentially taking down Opencast using a single HTTP request. To exploit this, users need to have ingest privileges, limiting the group of potential attackers The problem has been fixed in Opencast 9.6. There is no known workaround for this issue.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

1.25%

65.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-776

Affected Software

Vendor	Product	Versions
Apereo	Opencast	< 9.6

References

https://github.com/opencast/opencast/commit/8ae27da5a6f658011a5741b3210e715b0dc6213ePatch, Third Party Advisory
https://github.com/opencast/opencast/security/advisories/GHSA-9gwx-9cwp-5c2mExploit, Third Party Advisory
https://github.com/opencast/opencast/commit/8ae27da5a6f658011a5741b3210e715b0dc6213ePatch, Third Party Advisory
https://github.com/opencast/opencast/security/advisories/GHSA-9gwx-9cwp-5c2mExploit, Third Party Advisory

Timeline

Published: Jun 16, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-32623?

How severe is CVE-2021-32623?

CVE-2021-32623 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.25% probability of exploitation in the next 30 days.

How do I fix CVE-2021-32623?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-32623?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST