dbcve.org
HadoopApplication · Apache

CVE-2021-25642

HIGH · 8.8 CVSS v3.1 Published 2022-08-25
Fix available
A fix is available. Upgrade to 2.10.2 / 3.2.4 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
ZKConfigurationStore which is optionally used by CapacityScheduler of Apache Hadoop YARN deserializes data obtained from ZooKeeper without validation. An attacker having access to ZooKeeper can run arbitrary commands as YARN user by exploiting this. Users should upgrade to Apache Hadoop 2.10.2, 3.2.4, 3.3.4 or later (containing YARN-11126) if ZKConfigurationStore is used.

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

ZKConfigurationStore, an optional component of CapacityScheduler in Apache Hadoop YARN, deserializes data retrieved from ZooKeeper without proper validation. An attacker with ZooKeeper access can inject malicious serialized payloads to achieve remote code execution with YARN user privileges.

MitigationUpgrade to Apache Hadoop 2.10.2, 3.2.4, 3.3.4 or later (containing YARN-11126). If upgrading is not immediately feasible, verify that ZKConfigurationStore is not in use and consider disabling or restricting ZooKeeper access.

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
HadoopApplication
Affected:>= 2.9.0, < 2.10.2>= 3.0.0, < 3.2.4>= 3.3.0, < 3.3.4

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. Check installed Hadoop version
    Run `hadoop version` and note the version number in the output
    Affected if The version is 2.9.0 to 2.10.1, 3.0.0 to 3.2.3, or 3.3.0 to 3.3.3
  2. Verify ZKConfigurationStore is in use
    Inspect yarn-site.xml for the property `yarn.scheduler.capacity.store.class`. If set to `org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.ZKConfigurationStore`, ZKConfigurationStore is enabled.
    Affected if The `yarn.scheduler.capacity.store.class` property equals `org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.ZKConfigurationStore` (or the class name contains ZKConfigurationStore)
  3. Confirm ZooKeeper connection is configured
    Check yarn-site.xml for ZooKeeper-related properties used by CapacityScheduler, such as `yarn.scheduler.capacity.store.zk-address` or similar zk-store properties. Run `grep -i zk yarn-site.xml` to find any ZooKeeper configuration entries.
    Affected if ZooKeeper address or connection properties are defined in yarn-site.xml alongside ZKConfigurationStore class configuration

You are affected if your Hadoop version falls within the affected ranges AND ZKConfigurationStore is configured as the CapacityScheduler store class in yarn-site.xml.

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 2.10.2 / 3.2.4 / 3.3.4 or later
Fixed in 2.10.23.2.43.3.4
Interim mitigation

Upgrade to Apache Hadoop 2.10.2, 3.2.4, 3.3.4 or later (containing YARN-11126). If upgrading is not immediately feasible, verify that ZKConfigurationStore is not in use and consider disabling or restricting ZooKeeper access.

Recommended fix High confidence

Apache Hadoop 2.10.2, 3.2.4, or 3.3.4 (or later)

  1. Check if ZKConfigurationStore is enabled in your CapacityScheduler configuration (look for yarn.scheduler.capacity.zk-config.enabled property in yarn-site.xml)
  2. If ZKConfigurationStore is in use, plan upgrade to a fixed Hadoop version
  3. Test the upgrade in a non-production environment first
  4. Back up your Hadoop configuration and ZooKeeper data
  5. Perform the upgrade to Hadoop 2.10.2, 3.2.4, or 3.3.4 (or later) following Apache Hadoop upgrade documentation
  6. Verify CapacityScheduler and ZKConfigurationStore functionality after upgrade
Caveat Major version upgrades may require configuration changes; review Apache Hadoop upgrade guides for compatibility considerations

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

Fix this in Hadoop Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-25642 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-25642 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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