CVE-2020-5415: Concourse, versions prior to 6.3.1 and 6.4.1, in installations which use the GitLab auth connector, is vulnera

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CRITICAL 10.0REMOTEUPGRADE

CVE-2020-5415 is a critical-severity flaw (CVSS 10.0) affecting concourse. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	10.0 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.2% (top 31%)
CISA exploited list	No
Weakness	CWE-290
Published	2020-08-12
Last modified	2026-06-17

Publisher (CNA): Pivotal Software, Inc. · Vendor: pivotal software

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-08-12 17:15 UTCPublished CVE record published
2026-06-17 03:21 UTCUpdated Record last modified

pivotal software concourse UPGRADE

Affected: < 6.3.1 · >= 6.4.0 and < 6.4.1

Fixed in: 6.3.1, 6.4.1

Safe to downgrade to: a release before 6.4.0

1. Check installed version

apt-cache policy concourse || rpm -q concourse || concourse --version

2. UPGRADE to 6.3.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade concourse

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade concourse

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 6.4.0 (Debian / Ubuntu)

apt-cache madison concourse sudo apt install concourse=<VERSION_BEFORE_6.4.0> sudo apt-mark hold concourse

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list concourse sudo dnf downgrade concourse-<VERSION_BEFORE_6.4.0> sudo dnf versionlock add concourse

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-5415?

concourse: upgrade to 6.3.1, 6.4.1. Exact commands for each OS are on this page.

Is CVE-2020-5415 being exploited?

CVE-2020-5415 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-5415 affect?

CVE-2020-5415 affects concourse. Severity is critical (CVSS 10.0). 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

How urgent is CVE-2020-5415?

Priority 57/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

GitLab vulnerabilities

Related CVEs

CVE-2022-31683 MEDIUM 5.4 UPGRADE Concourse (7.x.y prior to 7.8.3 and 6.x.y prior to 6.7.9) contains an authorization bypass issue
CVE-2020-5409 MEDIUM 6.1 UPGRADE Pivotal Concourse, most versions prior to 6.0.0, allows redirects to untrusted websites in its login flow

References

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