title: Discourse BBCode plugin vulnerable to arbitrary CSS injection
description: discourse-bbcode is the official BBCode plugin for Discourse. Prior to commit 91478f5, CSS injection can occur when rendering content generated with the discourse-bccode plugin. This vulnerability only affects sites which have the discourse-bbcode plugin installed and enabled. This issue is patched in commit 91478f5. As a workaround, ensure that the Content Security Policy is enabled and monitor any posts that contain bbcode.
problem types: CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
affected:
{
vendor: discourse
product: discourse-bbcode
versions:
version: < 91478f5cfecdcc43cf85b997168a8ecfd0f8df90, status: affected
}
metrics:
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
attackVector: NETWORK
attackComplexity: LOW
privilegesRequired: LOW
userInteraction: NONE
scope: UNCHANGED
confidentialityImpact: HIGH
integrityImpact: HIGH
availabilityImpact: HIGH
baseScore: 8.8
baseSeverity: HIGH
]