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DubboApplication · Apache

CVE-2021-36162

HIGH · 8.8 CVSS v3.1 Published 2021-09-07
Fix available
A fix is available. Upgrade to after 3.0.1 or later.
See remediation →
94/100
Remediation priority · Urgent
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
Apache Dubbo supports various rules to support configuration override or traffic routing (called routing in Dubbo). These rules are loaded into the configuration center (eg: Zookeeper, Nacos, ...) and retrieved by the customers when making a request in order to find the right endpoint. When parsing these YAML rules, Dubbo customers will use SnakeYAML library to load the rules which by default will enable calling arbitrary constructors. An attacker with access to the configuration center he will be able to poison the rule so when retrieved by the consumers, it will get RCE on all of them. This was fixed in Dubbo 2.7.13, 3.0.2

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 uses SnakeYAML to parse routing rules from configuration centers. SnakeYAML's default settings permit arbitrary constructor invocation, enabling deserialization attacks. An attacker with write access to the configuration center can inject malicious YAML that executes arbitrary code on Dubbo consumers when they retrieve the poisoned rules.

MitigationUpgrade to Dubbo 2.7.13 or 3.0.2 or later. Additionally, enforce strict access controls on the configuration center (Zookeeper, Nacos, etc.) to prevent unauthorized rule injection.

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, <= 2.7.12>= 3.0.0, <= 3.0.1

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/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 Apache Dubbo installed version
    Check the Dubbo version in your pom.xml, build.gradle, or runtime dependency management. Run: mvn dependency:tree | grep dubbo or inspect the Dubbo jar manifest.
    Affected if Version is 2.7.0 through 2.7.12, or 3.0.0 through 3.0.1
  2. Confirm use of configuration center
    Review Dubbo configuration files (application.yml, dubbo.properties) or Spring context for properties under 'dubbo.config-center' or 'dubbo.registry' pointing to ZooKeeper, Nacos, Apollo, or Etcd.
    Affected if A configuration center (ZooKeeper, Nacos, Apollo, Etcd) is configured and in use
  3. Check SnakeYAML parser settings in Dubbo
    Inspect Dubbo source code or YAML parsing configuration for use of Yaml() or Yaml() constructor without SafeConstructor restriction. Search for 'new Yaml()' calls that do not pass a SafeConstructor.
    Affected if SnakeYAML is instantiated without a SafeConstructor, allowing arbitrary constructor invocation
  4. Verify configuration center write access controls
    Review ACLs, authentication settings, or role-based access controls on the configuration center (ZooKeeper ACLs, Nacos authentication, Apollo namespace permissions).
    Affected if Configuration center allows unauthenticated or unauthorized users to write routing rules

You are affected if Dubbo version is 2.7.0-2.7.12 or 3.0.0-3.0.1 AND uses a configuration center with SnakeYAML parsing that lacks SafeConstructor restrictions.

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 3.0.1
Interim mitigation

Upgrade to Dubbo 2.7.13 or 3.0.2 or later. Additionally, enforce strict access controls on the configuration center (Zookeeper, Nacos, etc.) to prevent unauthorized rule injection.

Recommended fix High confidence

Dubbo 2.7.13+ for 2.7.x line; Dubbo 3.0.2+ for 3.0.x line

  1. Identify your current Dubbo version by checking your pom.xml or dependency management
  2. If running Dubbo 2.7.x (2.7.0-2.7.12), upgrade to Dubbo 2.7.13 or later by updating the version in your dependency management
  3. If running Dubbo 3.0.x (3.0.0-3.0.1), upgrade to Dubbo 3.0.2 or later by updating the version in your dependency management
  4. After upgrading, rebuild and redeploy all affected consumer and provider services
  5. Verify the upgrade by testing that Dubbo applications function normally with your configuration center

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

Fix this in Dubbo Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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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-2021-36162 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