// For flags

CVE-2021-32623

Opencast vulnerable to billion laughs attack (XML bomb)

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

Opencast es una solución gratuita y de código abierto para la captura y distribución automática de vídeo. Las versiones de Opencast anteriores a versión 9.6 son vulnerables al ataque de los mil millones de risas, que permite a un atacante ejecutar fácilmente un ataque de denegación de servicio (aparentemente permanente), esencialmente derribando Opencast usando una única petición HTTP. Para explotar esto, los usuarios necesitan tener privilegios de ingesta, limitando el grupo de atacantes potenciales. El problema se ha corregido en Opencast versión 9.6. No se conoce ninguna solución para este problema

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
Single
Confidentiality
None
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-05-12 CVE Reserved
  • 2021-06-15 CVE Published
  • 2023-03-08 EPSS Updated
  • 2024-08-03 CVE Updated
  • 2024-08-03 First Exploit
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Apereo
Search vendor "Apereo"
Opencast
Search vendor "Apereo" for product "Opencast"
< 9.6
Search vendor "Apereo" for product "Opencast" and version " < 9.6"
-
Affected