CVE-2021-32623

Opencast vulnerable to billion laughs attack (XML bomb)

MEDIUM
6.5
CVSS Score
Published: June 15, 2021 at 11:45 PM UTC
Updated: June 17, 2026 at 03:53 AM UTC
2 products affected across 2 vendorsOpencastOpencast

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Severity
MEDIUM6.5
Exploit prediction
EPSS 1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 9.6
Affected range stops below 9.6, so it looks safe — our inference, not a vendor statement
v < 9.6
Affected range stops below 9.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-776

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