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ImpalaApplication · Apache

CVE-2017-5640

CRITICAL · 9.8 CVSS v3.0 Published 2017-07-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
It was noticed that a malicious process impersonating an Impala daemon in Apache Impala (incubating) 2.7.0 to 2.8.0 could cause Impala daemons to skip authentication checks when Kerberos is enabled (but TLS is not). If the malicious server responds with 'COMPLETE' before the SASL handshake has completed, the client will consider the handshake as completed even though no exchange of credentials has happened.

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 Impala 2.7.0-2.8.0 has a Kerberos authentication bypass where a malicious server impersonating an Impala daemon can send a 'COMPLETE' response before the SASL handshake finishes, causing clients to accept the connection without proper credential exchange when Kerberos is enabled but TLS is not.

MitigationEnable TLS/SSL in addition to Kerberos, or upgrade Impala to a version beyond 2.8.0 that contains the fix. The vulnerability requires both Kerberos to be enabled AND TLS to be disabled to be exploitable.

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
ImpalaApplication
Affected:= 2.7.0= 2.8.0

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

CVSS:3.0/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 Impala version
    Run 'impalad --version' or check the installed package version via package manager (e.g., 'rpm -q impala' or 'dpkg -l impala')
    Affected if The version is 2.7.0 or 2.8.0
  2. Verify if Kerberos authentication is enabled
    Inspect the Impala configuration files (typically in /etc/impala/conf or /opt/impala/conf) for 'krb5' or 'kerberos' related settings in impala-site.xml or flumeng-site.xml. Look for properties like 'impala.authentication' set to 'kerberos'
    Affected if Kerberos authentication is explicitly enabled in the Impala configuration
  3. Confirm TLS/SSL is disabled for Impala connections
    Check the Impala configuration for SSL settings. Look for 'ssl' or 'tls' related properties in impala-site.xml and verify they are disabled or absent. Check if 'impala.ssl.enabled' is set to false or if SSL-related certificate configurations are missing
    Affected if TLS/SSL is disabled or not configured for Impala daemon connections
  4. Determine if both conditions coexist
    Review the overall configuration: if Impala is at version 2.7.0 or 2.8.0 AND Kerberos is enabled AND TLS/SSL is disabled, the environment is vulnerable to this bypass
    Affected if All three conditions are true: affected version (2.7.0-2.8.0), Kerberos enabled, and TLS/SSL disabled

You are affected if Impala version is 2.7.0 or 2.8.0 with Kerberos authentication enabled while TLS/SSL is not enabled.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Enable TLS/SSL in addition to Kerberos, or upgrade Impala to a version beyond 2.8.0 that contains the fix. The vulnerability requires both Kerberos to be enabled AND TLS to be disabled to be exploitable.

Recommended fix High confidence

Impala 2.9.0 or later

  1. 1. Stop all Impala services (Impala Daemon, Catalog Server, StateStore)
  2. 2. Back up your current Impala configuration and any custom settings
  3. 3. Upgrade Impala from version 2.7.0 or 2.8.0 to version 2.9.0 or later
  4. 4. Review the release notes for version 2.9.0 to confirm the security fix for CVE-2017-5640 is included
  5. 5. Restart Impala services in the correct order: StateStore, Catalog Server, then Impala Daemon
  6. 6. Verify that Kerberos authentication is working correctly by connecting with a valid Kerberos principal
  7. 7. Test that the vulnerability is remediated by confirming clients cannot bypass authentication

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

Fix this in Impala Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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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-2017-5640 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