title: Concourse's GitLab auth allows impersonation
description: Concourse, versions prior to 6.3.1 and 6.4.1, in installations which use the GitLab auth connector, is vulnerable to identity spoofing by way of configuring a GitLab account with the same full name as another user who is granted access to a Concourse team. GitLab groups do not have this vulnerability, so GitLab users may be moved into groups which are then configured in the Concourse team.
problem types: CWE-290: Authentication Bypass by Spoofing
affected:
{
product: Concourse
vendor: VMware Tanzu
versions:
lessThan: 6.4.1, status: affected, version: 6.4, versionType: custom
lessThan: 6.3.1, status: affected, version: 6.3, versionType: custom
}
metrics:
cvssV3_0: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: LOW
baseScore: 10
baseSeverity: CRITICAL
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: NONE
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L
version: 3.0
]