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DubboApplication · Apache

CVE-2021-37579

CRITICAL · 9.8 CVSS v3.1 Published 2021-09-09
Fix available
A fix is available. Upgrade to 2.7.13 / 3.0.2 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
The Dubbo Provider will check the incoming request and the corresponding serialization type of this request meet the configuration set by the server. But there's an exception that the attacker can use to skip the security check (when enabled) and reaching a deserialization operation with native java serialization. Apache Dubbo 2.7.13, 3.0.2 fixed this issue by quickly fail when any unrecognized request was found.

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

Apache Dubbo's Provider includes security validation to verify incoming requests match configured serialization types. However, an exception in this validation logic allows attackers to bypass the security check and trigger native Java deserialization, leading to remote code execution. The fix implements fail-fast behavior when unrecognized requests are detected.

MitigationUpgrade to Apache Dubbo 2.7.13, 3.0.2, or later which introduces fail-fast behavior for unrecognized requests to prevent the bypass.

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
DubboApplication
Affected:>= 2.7.0, < 2.7.13>= 3.0.0, < 3.0.2

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 installed Apache Dubbo version
    Locate the Dubbo JAR file or check the pom.xml dependencies for the org.apache.dubbo groupId artifact version
    Affected if The version is 2.7.0 through 2.7.12, or 3.0.0 through 3.0.1 (falls within >= 2.7.0 < 2.7.13 or >= 3.0.0 < 3.0.2)
  2. Verify Java deserialization is in use
    Check Dubbo configuration files (dubbo.properties, dubbo.xml, or Spring configuration) for serialization.type or hessian.serialization settings
    Affected if The serialization type is set to a Java-native deserializer such as java, hessian, or json without a strict whitelist configured
  3. Confirm provider accepts arbitrary serialization headers
    Inspect network traffic or application logs for incoming Dubbo requests with the 'serialization' header set to values not explicitly allowed in the provider's whitelist
    Affected if The provider accepts serialization type headers from clients without rejecting unrecognized types with an error
  4. Check for fail-fast validation behavior
    Send a test Dubbo request with an invalid or unrecognized serialization type and observe whether the provider rejects it immediately or attempts deserialization
    Affected if The provider does not fail-fast (reject immediately) on unrecognized serialization types and instead attempts to process the request using default deserialization

You are affected if your Dubbo version falls within 2.7.0-2.7.12 or 3.0.0-3.0.1 AND your provider accepts serialization type headers that are not explicitly whitelisted, allowing the security validation bypass.

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 2.7.13 / 3.0.2 or later
Fixed in 2.7.133.0.2
Interim mitigation

Upgrade to Apache Dubbo 2.7.13, 3.0.2, or later which introduces fail-fast behavior for unrecognized requests to prevent the bypass.

Recommended fix High confidence

Dubbo 2.7.13 (for 2.7.x branches) or Dubbo 3.0.2 (for 3.0.x branches)

  1. 1. Identify the current Dubbo version in use (check pom.xml, dependency management, or running application)
  2. 2. If using Dubbo 2.7.x series: plan upgrade to version 2.7.13 or later
  3. 3. If using Dubbo 3.0.x series: plan upgrade to version 3.0.2 or later
  4. 4. Update the Dubbo dependency version in pom.xml or build configuration to the target fixed version
  5. 5. Rebuild and redeploy the Dubbo application with the updated dependency
  6. 6. Verify the application starts correctly and all services are functioning
  7. 7. Test that the security fix is active by confirming the rapid fail behavior on unrecognized requests
Caveat Review Dubbo release notes between current version and target version for any breaking changes in APIs, configuration, or default behaviors; major version upgrades (2.7 to 3.0) may require more extensive testing

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

Fix this in Dubbo Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA3.0 h
18.0 hours of engineering $3,060
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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-2021-37579 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