dbcve.org
NomadApplication · Hashicorp

CVE-2020-7956

CRITICAL · 9.8 CVSS v3.1 Published 2020-01-31
Fix available
A fix is available. Upgrade to 0.10.3 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
HashiCorp Nomad and Nomad Enterprise up to 0.10.2 incorrectly validated role/region associated with TLS certificates used for mTLS RPC, and were susceptible to privilege escalation. Fixed in 0.10.3.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Nomad up to 0.10.2 incorrectly validated the role/region fields in TLS certificates used for mTLS RPC communication. This improper certificate validation allowed attackers to bypass authentication controls and escalate privileges by presenting crafted certificates with modified role/region claims.

MitigationUpgrade Nomad to version 0.10.3 or later, which implements proper validation of role/region fields in TLS certificates for mTLS RPC. Verify mTLS configuration works correctly after the upgrade.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
NomadApplication
Affected:< 0.10.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Nomad version
    Run 'nomad version' or check the binary version. If using a package manager, query the installed package.
    Affected if The installed version is less than 0.10.3
  2. Identify if mTLS RPC is enabled
    Inspect the Nomad configuration files (typically in /etc/nomad.d/ or specified via -config flag). Look for 'tls' blocks with 'enable_tls' or 'verify_https_client' settings. Check for certificates specified via 'cert_file' and 'key_file' in the client and server RPC communication settings.
    Affected if mTLS is configured and enabled for RPC communication between Nomad clients and servers
  3. Verify certificate validation configuration
    In the Nomad configuration, examine the TLS settings for 'verify_server_hostname', 'verify_https_client', and any role/region specific certificate validation options. Check if 'nomad tls' commands are used for certificate management.
    Affected if Role or region fields in certificates are not validated, or custom certificates with role/region claims are in use without proper validation checks

A user is affected if running Nomad version 0.10.2 or earlier AND has mTLS RPC communication enabled with certificates containing role/region claims that are not being properly validated.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 0.10.3 or later
Fixed in 0.10.3
Interim mitigation

Upgrade Nomad to version 0.10.3 or later, which implements proper validation of role/region fields in TLS certificates for mTLS RPC. Verify mTLS configuration works correctly after the upgrade.

Recommended fix High confidence

Nomad 0.10.3 (or later stable release)

  1. 1. Backup your Nomad data directory and configuration files before upgrading
  2. 2. Download HashiCorp Nomad version 0.10.3 from the official releases page (www.hashicorp.com/products/nomad/releases) or GitHub (github.com/hashicorp/nomad)
  3. 3. Stop the Nomad service on all cluster nodes
  4. 4. Replace the Nomad binary with version 0.10.3 on all cluster nodes
  5. 5. Verify the Nomad configuration files are intact
  6. 6. Start the Nomad service on cluster nodes, starting with the servers first
  7. 7. Verify the cluster is healthy using 'nomad server members' or 'nomad status'
  8. 8. Confirm the version upgrade with 'nomad version' showing 0.10.3
Caveat Review Nomad 0.10.3 release notes for any breaking changes; mTLS configuration may require adjustment after certificate validation improvements

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Nomad Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
24.0 hours of engineering $4,160
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-7956 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data