SolrApplication · Apache
CVE-2021-29262
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 · uneditedWhen starting Apache Solr versions prior to 8.8.2, configured with the SaslZkACLProvider or VMParamsAllAndReadonlyDigestZkACLProvider and no existing security.json znode, if the optional read-only user is configured then Solr would not treat that node as a sensitive path and would allow it to be readable. Additionally, with any ZkACLProvider, if the security.json is already present, Solr will not automatically update the ACLs.
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 confidenceApache Solr versions before 8.8.2 have two ACL vulnerabilities: (1) When using SaslZkACLProvider or VMParamsAllAndReadonlyDigestZkACLProvider with no existing security.json and a read-only user configured, Solr fails to protect that node as sensitive, making it publicly readable; (2) When security.json already exists, any ZkACLProvider will not automatically update ACLs, leaving potential misconfigurations unfixed. This allows unauthorized disclosure of sensitive ZooKeeper paths.
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
SolrApplication
< 8.8.2CVSS 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
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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 checksWork through these to decide whether this CVE applies to you.
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Check Apache Solr versionRun 'solr version' command or inspect the Solr admin UI for the installed versionAffected if Version is earlier than 8.8.2
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Locate security.json in ZooKeeperQuery ZooKeeper for the path /solr/security.json using zkCli.sh or similar tool to determine if a security.json file existsAffected if No security.json exists, or the file exists but was not automatically updated by the ZkACLProvider
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Identify the configured ZkACLProviderExamine security.json for the 'acl' or 'aclClass' setting to determine which ZkACLProvider is in useAffected if The ACL provider is SaslZkACLProvider or VMParamsAllAndReadonlyDigestZkACLProvider
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Verify ACLs on sensitive pathsList ZooKeeper nodes under /solr and inspect ACL permissions on paths that should be sensitive, particularly paths accessible to read-only usersAffected if Sensitive paths are publicly readable or lack proper ACL restrictions when using the affected providers
Apache Solr is affected if running version earlier than 8.8.2 with SaslZkACLProvider or VMParamsAllAndReadonlyDigestZkACLProvider, especially when security.json is missing or ACLs were not automatically applied to sensitive paths.
Generated from the published advisory. Verify against your own configuration.
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 data8.8.2
Upgrade to Apache Solr 8.8.2 or later. Review and recreate security.json with explicit ACL configurations to ensure sensitive paths are properly protected, regardless of whether an existing security.json is present.
Fix this in Solr
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-29262 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-29262 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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