TI-2020-09954 Aliases CVE-2020-12443 GHSA-hp96-66jq-q83w

BigBlueButton before 2.2.6 allows remote attackers to read arbitrary files because the…

MEDIUM 48CWE-22Published 2020-04-29 · Updated 2024-08-04

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · High · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA.

Summary

BigBlueButton before 2.2.6 allows remote attackers to read arbitrary files because the presfilename (lowercase) value can be a .pdf filename while the presFilename (mixed case) value has a ../ sequence. This can be leveraged for privilege escalation via a directory traversal to bigbluebutton.properties. NOTE: this issue exists because of an ineffective mitigation to CVE-2020-12112 in which there was an attempted fix within an NGINX configuration file, without considering that the relevant part of NGINX is case-insensitive.

Why it matters now

EPSS 0.03659 89th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
—	—	all versions	—	No fix listed	CNA

— Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:bigbluebutton:bigbluebutton::::::::	before 2.2.6	Vulnerable	bigbluebutton

cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:* Versions before 2.2.6 Vulnerable ·bigbluebutton

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2020-12443
2026-10-03 Alias added: GHSA-hp96-66jq-q83w

References

Exploit 1

https://github.com/mclab-hbrs/BBB-POC

Patch 1

https://github.com/bigbluebutton/bigbluebutton/pull/9259/commits/b21ca8355a57286a1e6df96984b3a4c57679a463

TI-2026-21873 BigBlueButton: Exposed ClamAV port enables Denial of Service CVSS 3.1HIGH 8.2
TI-2025-38047 BigBlueButton vulnerable to Chat DoS via invalid reactionEmojiId CVSS 3.1HIGH 7.5
TI-2025-38046 BigBlueButton vulnerable to DoS via PollSubmitVote GraphQL mutation CVSS 3.1HIGH 7.5
TI-2022-13109 Cross site scripting in username that will trigger by sending chat CVSS 3.1MEDIUM 6.5
TI-2020-16722 BigBlueButton through 2.2.28 uses Ghostscript for processing of uploaded EPS documents… CVSS 3.1CRITICAL 9.8
TI-2020-16719 BigBlueButton before 2.2.7 does not have a protection mechanism for separator injection… CVSS 3.1CRITICAL 9.8

See all 48 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences