title: Improper access control for pencil annotations in BigBlueButton
description: BigBlueButton is an open source web conferencing system. Starting in version 2.2 and prior to versions 2.3.18 and 2.4-rc-6, an attacker can circumvent access restrictions for drawing on the whiteboard. The permission check is inadvertently skipped on the server, due to a previously introduced grace period. The attacker must be a meeting participant. The problem has been patched in versions 2.3.18 and 2.4-rc-6. There are currently no known workarounds.
problem types: CWE-285: Improper Authorization
affected:
{
vendor: bigbluebutton
product: bigbluebutton
versions:
version: >= 2.2, < 2.3.18, status: affected
version: >= 2.4-alpha-1, < 2.4-rc-6, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 4.3
baseSeverity: MEDIUM
confidentialityImpact: LOW
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
version: 3.1
]