CVE-2021-32623CWE-776

Opencast vulnerable to billion laughs attack (XML bomb)

High · published June 15, 2021

CVSS v3.1
8.1
EPSS
1%
Percentile
69.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.01254 · 69.3th percentile
Weakness
CWE-776 · Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
Published
2021-06-15T23:45Z
EPSS history
Timeline
  • 15 JUN 23:45Z
    Opencast vulnerable to billion laughs attack (XML bomb)
    cvelistv5