What’s Vulnerable › Vulnerabilities

CVE-2020-5415: Concourse's GitLab auth allows impersonation

• Severity: critical (CVSS 10.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-08-12 · updated 2026-06-17
• Weakness: CWE-290

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.

Affected products

• Pivotal Concourse: before 6.3.1; from 6.4.0 before 6.4.1 — fixed in 6.3.1, 6.4.1

How to fix

Upgrade to a fixed version: Pivotal Concourse 6.3.1, 6.4.1. Check the vendor advisory for mitigations.

References

• https://github.com/concourse/concourse/security/advisories/GHSA-627p-rr78-99rj
• https://tanzu.vmware.com/security/cve-2020-5415
• https://github.com/concourse/concourse/security/advisories/GHSA-627p-rr78-99rj
• https://tanzu.vmware.com/security/cve-2020-5415

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