PT-2020-16714 · Bigbluebutton+1 · Bigbluebutton+1

Published 2020-10-21 · Updated 2020-10-30 · CVE-2020-27604

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions BigBlueButton versions prior to 2.3

Description The issue is related to the lack of LibreOffice sandboxing, which could allow remote authenticated users to read the API shared secret in the bigbluebutton.properties file. With access to the API shared secret, an attacker can use the "api/join" endpoint to join an arbitrary meeting, regardless of its guestPolicy setting.

Recommendations For versions prior to 2.3, update to version 2.3 or later to resolve the issue. As a temporary workaround, consider restricting access to the bigbluebutton.properties file to minimize the risk of the API shared secret being read. Avoid using the api/join endpoint with arbitrary meeting IDs until the issue is resolved.

Exploit

Fix

Improper Encoding or Escaping of Output

Weakness Enumeration

CWE-116

Related Identifiers

CVE-2020-27604

Affected Products

Bigbluebutton

Libreoffice

References · 4

• 🔥 https://golem.de/news/big-blue-button-das-grosse-blaue-sicherheitsrisiko-2010-151610.html · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2020-27604 · Security Note
• https://osv.dev/vulnerability/CVE-2020-27604 · Vendor Advisory
• https://docs.bigbluebutton.org/dev/api.html · Note