cve.bz

CVE-2020-12443

9.8 criticalEPSS 3.7%

Critical (9.8) in bigbluebutton bigbluebutton. EPSS 3.7% chance of exploitation in the next 30 days.

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.

Severity

CVSS 3.1

9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
3.7% chance of exploitation in the next 30 days; higher than 89% of CVEs (scores of 2026-10-31)
CWE
CWE-22
Published
Modified
Record from
the NVD, synced

Affected

References

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