dbcve.org
SolrApplication · Apache

CVE-2017-9803

HIGH · 7.5 CVSS v3.0 Published 2017-09-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
81/100
Remediation priority · High
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 Solr's Kerberos plugin can be configured to use delegation tokens, which allows an application to reuse the authentication of an end-user or another application. There are two issues with this functionality (when using SecurityAwareZkACLProvider type of ACL provider e.g. SaslZkACLProvider). Firstly, access to the security configuration can be leaked to users other than the solr super user. Secondly, malicious users can exploit this leaked configuration for privilege escalation to further expose/modify private data and/or disrupt operations in the Solr cluster. The vulnerability is fixed from Apache Solr 6.6.1 onwards.

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 Solr's Kerberos plugin delegation token feature, when using SecurityAwareZkACLProvider (SaslZkACLProvider), improperly exposes security configuration to non-super users. This information disclosure allows malicious authenticated users to perform privilege escalation and modify or access private data within the Solr cluster.

MitigationUpgrade Apache Solr to version 6.6.1 or later. If upgrading is not immediately feasible, review and restrict ZooKeeper ACLs and disable delegation token functionality if not required.

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
Affected:= 6.2.0= 6.2.1= 6.3.0= 6.4.0= 6.4.1= 6.4.2= 6.5.0= 6.5.1= 6.6.0

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
High
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:H/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 installed Apache Solr version
    Run `bin/solr version` or check the Solr admin UI footer for the version number, or inspect the JAR file `lucene-core-*.jar` in the installation directory
    Affected if Version is 6.2.0, 6.2.1, 6.3.0, 6.4.0, 6.4.1, 6.4.2, 6.5.0, 6.5.1, or 6.6.0
  2. Verify Kerberos authentication is configured
    Examine the Solr security configuration in ZooKeeper under `/solr/security` or check `security.json` for `authentication` block with `kerberos` type
    Affected if Kerberos authentication is enabled in the Solr cluster
  3. Confirm SecurityAwareZkACLProvider is in use
    Check ZooKeeper for the ACL provider configuration under `/solr/security` or review `security.json` for the `authorization` plugin configuration containing `SaslZkACLProvider` or `SecurityAwareZkACLProvider`
    Affected if The ACL provider is set to SaslZkACLProvider or SecurityAwareZkACLProvider
  4. Determine if delegation token feature is enabled
    Inspect the security configuration for delegation token settings, typically found in the authentication plugin configuration in `security.json` or the Solr admin security page
    Affected if Delegation token functionality is enabled in the Kerberos authentication configuration

If running an affected Solr version AND using Kerberos authentication with SecurityAwareZkACLProvider AND delegation tokens are enabled, the environment is vulnerable to this information disclosure flaw.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Apache Solr to version 6.6.1 or later. If upgrading is not immediately feasible, review and restrict ZooKeeper ACLs and disable delegation token functionality if not required.

Fix this in Solr Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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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-2017-9803 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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