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MuleApplication · Salesforce

CVE-2021-1626

CRITICAL · 9.8 CVSS v3.1 Published 2021-03-26
Fix available
A fix is available. Upgrade to after 4.2.2 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
MuleSoft is aware of a Remote Code Execution vulnerability affecting certain versions of a Mule runtime component that may affect both CloudHub and on-premise customers. Versions affected: Mule 4.1.x and 4.2.x runtime released before February 2, 2021.

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 · moderate confidence

A Remote Code Execution vulnerability in MuleSoft Mule runtime 4.1.x and 4.2.x versions released prior to February 2, 2021 allows attackers to execute arbitrary code on affected CloudHub and on-premise deployments.

MitigationUpgrade Mule runtime to a version released on or after February 2, 2021, or apply vendor-supplied patches; for CloudHub users, ensure the runtime is updated to a patched version via the CloudHub console.

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
MuleApplication
Affected:>= 4.1.0, <= 4.2.2

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. Identify Mule runtime version in use
    For on-premise deployments, locate the mule runtime installation directory and check the wrapper.conf file (typically in the /conf/ folder) for the product.version property, or run the command 'mule -version' if available. For CloudHub deployments, log into the CloudHub console and navigate to the Runtime Manager to view the runtime version assigned to your worker(s).
    Affected if The version shown is 4.1.0, 4.1.1, 4.1.2, 4.1.3, 4.1.4, 4.2.0, 4.2.1, or 4.2.2 (any version from 4.1.0 through 4.2.2 inclusive).
  2. Confirm the release date of the installed version
    Check the MuleSoft release notes or the runtime version metadata to determine when this specific version was released. The vulnerability applies to versions released before February 2, 2021.
    Affected if The installed version was released prior to February 2, 2021 and falls within the 4.1.x or 4.2.x branch.
  3. Verify if the RCE vector is accessible
    This vulnerability allows arbitrary code execution. Determine if the Mule runtime is exposed to untrusted input through any exposed API endpoints, HTTP listeners, or third-party integrations that could trigger the vulnerable code path.
    Affected if The runtime processes untrusted input or scripts without strict sandboxing and the version is within the affected range.

You are affected if your Mule runtime version is 4.1.0 through 4.2.2 inclusive and was released before the February 2021 patch date.

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 a release after 4.2.2
Interim mitigation

Upgrade Mule runtime to a version released on or after February 2, 2021, or apply vendor-supplied patches; for CloudHub users, ensure the runtime is updated to a patched version via the CloudHub console.

Recommended fix High confidence

Mule runtime 4.3.0 or later (versions released after February 2, 2021 contain the fix)

  1. Identify your current Mule runtime version using the Mule management console or runtime manager
  2. Plan maintenance window for upgrade as this requires restart
  3. For on-premise deployments: Download Mule runtime 4.3.0 or later from MuleSoft's download site
  4. For CloudHub deployments: Contact MuleSoft support or use the runtime manager to schedule upgrade to a fixed version
  5. Before upgrading, review MuleSoft release notes for any known issues or migration requirements
  6. Backup your current applications and configuration
  7. Deploy the new runtime version
  8. Verify all applications are running correctly after upgrade
Caveat Review release notes for any breaking changes between 4.2.x and 4.3.x; some connector or API compatibility adjustments may be needed

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

Fix this in Mule Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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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-2021-1626 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