title: Discourse CSP nonce reuse vulnerability for anonymous users
description: Discourse is an open source discussion platform. Prior to version 3.1.0.beta7 of the `beta` and `tests-passed` branches, a CSP (Content Security Policy) nonce reuse vulnerability was discovered could allow cross-site scripting (XSS) attacks to bypass CSP protection for anonymous (i.e. unauthenticated) users. There are no known XSS vectors at the moment, but should one be discovered, this vulnerability would allow the XSS attack to bypass CSP and execute successfully. This vulnerability isn't applicable to logged-in users. Version 3.1.0.beta7 contains a patch. The stable branch doesn't have this vulnerability. A workaround to prevent the vulnerability is to disable Google Tag Manager, i.e., unset the `gtm container id` setting.
problem types: CWE-323: Reusing a Nonce, Key Pair in Encryption
affected:
{
vendor: discourse
product: discourse
versions:
version: >= 3.1.0.beta1, < 3.1.0.beta7, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 6.8
baseSeverity: MEDIUM
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
version: 3.1
]