dbcve.org
MongoDBDatabase / datastore

CVE-2019-20923

MEDIUM · 6.5 CVSS v3.1 Published 2020-11-23
Fix available
A fix is available. Upgrade to 4.0.7 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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
A user authorized to perform database queries may trigger denial of service by issuing specially crafted queries, which throw unhandled Javascript exceptions containing types intended to be scoped to the Javascript engine's internals. This issue affects MongoDB Server v4.0 versions prior to 4.0.7.

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

A user authorized to perform database queries can trigger denial of service in MongoDB Server v4.0 prior to 4.0.7 by issuing specially crafted queries that cause unhandled JavaScript exceptions containing internal JavaScript engine type definitions.

MitigationUpgrade MongoDB Server to version 4.0.7 or later to patch this vulnerability.

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
MongoDBDatabase / datastore
Affected:>= 4.0.0, < 4.0.7

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 MongoDB server version
    Run 'db.version()' in mongosh/mongo shell, or run 'mongod --version' from command line, or check the package manager
    Affected if The version is 4.0.0 through 4.0.6 (inclusive)
  2. Verify JavaScript execution is enabled
    Check the mongod configuration file (typically /etc/mongod.conf) or run 'db.adminCommand({getParameter: 1, javascriptEnabled: 1})' to confirm JavaScript is enabled
    Affected if JavaScript is enabled (this is the default in affected versions)
  3. Confirm user database query permissions exist
    Run 'db.getUsers()' or 'db.getRoles()' on any database to list users and their roles; check for users with roles that include 'find', 'insert', 'update', or 'remove' privileges
    Affected if Any user exists with database query permissions (required for exploitation)

You are affected if your MongoDB version is between 4.0.0 and 4.0.6 inclusive and you have users with database query permissions (which is typical).

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.

From vendor data
Upgrade available Upgrade to 4.0.7 or later
Fixed in 4.0.7
Interim mitigation

Upgrade MongoDB Server to version 4.0.7 or later to patch this vulnerability.

Fix this in MongoDB Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

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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-2019-20923 in production — separate from our analysis above.

No notes yet

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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