XXE in Apereo Opencast

CVE-2021-32623

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.

EPSS: 0.013 (67.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-32623?
CVE-2021-32623 is a high-severity vulnerability in Apereo Opencast, classified under Improper Restriction of Recursive Entity References in DTDs (XML Entity Expansion). CVSS score: 8.1/10. Published 2021-06-16.
How severe is CVE-2021-32623?
High severity. CVSS v3 base score is 8.1 out of 10.