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PulsarApplication · Apache

CVE-2023-37544

HIGH · 7.5 CVSS v3.1 Published 2023-12-20
Fix available
A fix is available. Upgrade to 2.10.5 / 2.11.2 or later.
See remediation →
84/100
Remediation priority · High
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
Improper Authentication vulnerability in Apache Pulsar WebSocket Proxy allows an attacker to connect to the /pingpong endpoint without authentication. This issue affects Apache Pulsar WebSocket Proxy: from 2.8.0 through 2.8.*, from 2.9.0 through 2.9.*, from 2.10.0 through 2.10.4, from 2.11.0 through 2.11.1, 3.0.0. The known risks include a denial of service due to the WebSocket Proxy accepting any connections, and excessive data transfer due to misuse of the WebSocket ping/pong feature. 2.10 Pulsar WebSocket Proxy users should upgrade to at least 2.10.5. 2.11 Pulsar WebSocket Proxy users should upgrade to at least 2.11.2. 3.0 Pulsar WebSocket Proxy users should upgrade to at least 3.0.1. 3.1 Pulsar WebSocket Proxy users are unaffected. Any users running the Pulsar WebSocket Proxy for 2.8, 2.9, and earlier should upgrade to one of the above patched versions.

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

Improper authentication in Apache Pulsar WebSocket Proxy allows unauthenticated access to the /pingpong endpoint, enabling attackers to establish connections without credentials. This can be exploited for denial of service via excessive connections and abuse of WebSocket ping/pong frames for unauthorized data transfer.

MitigationUpgrade Apache Pulsar WebSocket Proxy to version 2.10.5, 2.11.2, 3.0.1, or later to add authentication requirements to the /pingpong endpoint.

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
PulsarApplication
Affected:< 2.10.5>= 2.11.0, < 2.11.2= 3.0.0

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 Apache Pulsar version
    Run 'pulsar version' or check the version file in the Pulsar installation directory (e.g., VERSION file in the pulsar root or in the lib/ directory)
    Affected if The installed version is < 2.10.5, or between 2.11.0 and 2.11.1 inclusive, or exactly 3.0.0
  2. Confirm WebSocket Proxy is enabled
    Check the Pulsar broker configuration file (broker.conf or standalone.conf) for 'webSocketServiceEnabled=true' or verify that the WebSocket package is loaded
    Affected if WebSocket Proxy is enabled (the vulnerability only applies when this service is running)
  3. Check authentication configuration for WebSocket endpoints
    Review the Pulsar authentication/authorization configuration files for the WebSocket plugin. Look for settings controlling authentication on the /pingpong endpoint specifically
    Affected if Authentication is not explicitly required for the /pingpong endpoint in the configuration (the vulnerability exists when /pingpong allows unauthenticated access)
  4. Verify unauthenticated /pingpong endpoint accessibility
    If you have network access to the Pulsar WebSocket proxy port (typically 8080 or 8082), attempt a curl or similar request to http://<pulsar-host>:<port>/pingpong without providing any credentials
    Affected if The /pingpong endpoint responds successfully without authentication headers or tokens (this confirms the vulnerable condition)

You are affected if your Pulsar version falls within the vulnerable ranges (pre-2.10.5, 2.11.0-2.11.1, or 3.0.0) AND the WebSocket Proxy is enabled AND the /pingpong endpoint accepts unauthenticated requests.

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 2.10.5 / 2.11.2 or later
Fixed in 2.10.52.11.2
Interim mitigation

Upgrade Apache Pulsar WebSocket Proxy to version 2.10.5, 2.11.2, 3.0.1, or later to add authentication requirements to the /pingpong endpoint.

Recommended fix High confidence

Upgrade to Pulsar 2.10.5, 2.11.2, or 3.0.1 (or later releases within each respective branch)

  1. 1. Identify the currently running Apache Pulsar version by checking the Pulsar broker or WebSocket Proxy service version.
  2. 2. Determine which upgrade path applies based on your current version: if on 2.8.x or 2.9.x, upgrade to 2.10.5 or later; if on 2.10.x, upgrade to 2.10.5 or later; if on 2.11.x, upgrade to 2.11.2 or later; if on 3.0.0, upgrade to 3.0.1.
  3. 3. Review the Apache Pulsar upgrade documentation for your current version to ensure a safe upgrade path.
  4. 4. Stop the Pulsar WebSocket Proxy service.
  5. 5. Upgrade the Pulsar installation to the appropriate fixed version (2.10.5, 2.11.2, or 3.0.1).
  6. 6. Restart the Pulsar WebSocket Proxy service.
  7. 7. Verify that the /pingpong endpoint now requires authentication and that unauthorized access is no longer possible.

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

Fix this in Pulsar Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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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-2023-37544 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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