CVE-2021-33845
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 · uneditedThe Splunk Enterprise REST API allows enumeration of usernames via the lockout error message. The potential vulnerability impacts Splunk Enterprise instances before 8.1.7 when configured to repress verbose login errors.
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 confidenceThe Splunk Enterprise REST API allows username enumeration through lockout error messages. Even when configured to repress verbose login errors, the API still differentiates between valid and invalid usernames based on the lockout response, allowing attackers to discover valid usernames for further attacks.
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>= 8.1.0, < 8.1.7CVSS 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
- Low
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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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Verify Splunk Enterprise versionRun 'splunk --version' or check $SPLUNK_HOME/etc/splunk.version file to obtain the installed version number.Affected if The installed version is 8.1.0, 8.1.1, 8.1.2, 8.1.3, 8.1.4, 8.1.5, or 8.1.6 (any version >= 8.1.0 but < 8.1.7).
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Confirm REST API exposureReview network configuration and Splunk web.conf settings to determine if the Splunk REST API port (default 8089) is accessible from untrusted networks.Affected if The REST API port 8089 is exposed to the internet or untrusted internal networks.
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Check authentication response behaviorSend a test login request with a valid username but incorrect password, then send the same request with a clearly invalid username. Compare the HTTP response codes and messages returned for each case.Affected if The responses differ between valid and invalid usernames (e.g., valid username triggers account lockout messaging while invalid username returns a different error).
You are affected if your Splunk Enterprise version is between 8.1.0 and 8.1.6 inclusive and the REST API is network-accessible to potential attackers.
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.
dbcve · scoped8.1.7
Upgrade Splunk Enterprise to version 8.1.7 or later where this issue is resolved.
8.1.7 or later
- Upgrade Splunk Enterprise to version 8.1.7 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-33845 — 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-2021-33845 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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- 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
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