title: Prevent user enumeration using Guard or the new Authenticator-based Security
description: Symfony is a PHP framework for web and console applications and a set of reusable PHP components. The ability to enumerate users was possible without relevant permissions due to different handling depending on whether the user existed or not when attempting to use the switch users functionality. We now ensure that 403s are returned whether the user exists or not if a user cannot switch to a user or if the user does not exist. The patch for this issue is available for branch 3.4.
problem types: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
affected:
{
vendor: symfony
product: symfony
versions:
version: >= 2.8.0, < 3.4.48, status: affected
version: >= 4.0.0, < 4.4.23, status: affected
version: >= 5.0.0, < 5.2.8, status: affected
}
metrics:
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
attackVector: NETWORK
attackComplexity: LOW
privilegesRequired: NONE
userInteraction: NONE
scope: UNCHANGED
confidentialityImpact: LOW
integrityImpact: NONE
availabilityImpact: NONE
baseScore: 5.3
baseSeverity: MEDIUM
]