Description
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.
Published: 2020-04-29
Score: 9.8 Critical
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2020-4754 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.
History

Sun, 13 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00611}

epss

{'score': 0.00847}


Sat, 12 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00464}

epss

{'score': 0.00611}


Subscriptions

Bigbluebutton Bigbluebutton
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2024-08-04T11:56:52.060Z

Reserved: 2020-04-29T00:00:00.000Z

Link: CVE-2020-12443

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2020-04-29T02:15:11.467

Modified: 2024-11-21T04:59:43.700

Link: CVE-2020-12443

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses