CVE Vulnerability

CVE-2020-12443

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.

7.5 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 10 / Impact : 6.4

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

Scope

9.8 /10

CVSS v3.0 : CRITICAL

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://github.com/bigbluebutton/bigbluebutton/pull/9259/commits/b21ca8355a57286a1e6df96984b3a4c57679a463 Patch Third Party Advisory
https://github.com/mclab-hbrs/BBB-POC Exploit Third Party Advisory
Configurations

Configuration 1

cpe:2.3:a:bigbluebutton:bigbluebutton:*:*:*:*:*:*:*:*
Information

Published : 2020-04-29 02:15

Updated : 2020-05-06 02:02

NVD link : CVE-2020-12443

Mitre link : CVE-2020-12443

Products Affected
No products.
CWE
CWE-22