title: Stored cross site scripting (XSS) vulnerability via Authorization Endpoint in user_oidc
description: user_oidc is an OpenID Connect user backend for Nextcloud. Versions prior to 1.2.1 did not properly validate discovery urls which may lead to a stored cross site scripting attack vector. The impact is limited due to the restrictive CSP that is applied on this endpoint. Additionally this vulnerability has only been shown to be exploitable in the Safari web browser. This issue has been addressed in version 1.2.1. Users are advised to upgrade. Users unable to upgrade should urge their users to avoid using the Safari web browser.
problem types: CWE-20: Improper Input Validation
affected:
{
vendor: nextcloud
product: security-advisories
versions:
version: < 1.2.1, status: affected
}
metrics:
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N
attackVector: NETWORK
attackComplexity: LOW
privilegesRequired: HIGH
userInteraction: REQUIRED
scope: UNCHANGED
confidentialityImpact: LOW
integrityImpact: LOW
availabilityImpact: NONE
baseScore: 3.5
baseSeverity: LOW
]