How severe is CVE-2023-37544?

CVE-2023-37544 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-37544?

CVE-2023-37544 affects the following packages: org.apache.pulsar:pulsar-websocket (Maven), org.apache.pulsar:pulsar-websocket (Maven), org.apache.pulsar:pulsar-websocket (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-37544?

Update org.apache.pulsar:pulsar-websocket to 2.10.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-37544 is resolved across your whole dependency graph.

How do I detect CVE-2023-37544 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.pulsar:pulsar-websocket. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2023-37544 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2023-37544?

O3 pinpoints whether CVE-2023-37544 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2023-37544 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-37544 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-37544?

CVE-2023-37544 has an EPSS (Exploit Prediction Scoring System) score of 1.4%, placing it in the 68th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2023-37544 published, and has it been updated?

CVE-2023-37544 was published on December 20, 2023 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

CVE-2023-37544

HIGH

Apache Pulsar WebSocket Proxy contains an Improper Authentication vulnerability

Also known asGHSA-83q5-whqp-r8jr

Published

Dec 20, 2023

Updated

Apr 10, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

1.4%probability of exploitation in next 30 days

Lower Risk68th percentile+1.28%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

3 pkgs affected

☕org.apache.pulsar:pulsar-websocket☕org.apache.pulsar:pulsar-websocket☕org.apache.pulsar:pulsar-websocket

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.apache.pulsar:pulsar-websocket`	all versions	2.10.5
☕Maven	`org.apache.pulsar:pulsar-websocket`	≥ 2.11.0&&< 2.11.2	2.11.2
☕Maven	`org.apache.pulsar:pulsar-websocket`	≥ 3.0.0&&< 3.0.1	3.0.1

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.pulsar:pulsar-websocket. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.apache.pulsar:pulsar-websocket to 2.10.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-37544 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2023-37544 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2023-37544. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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 sh

O3 Security · Impact-Aware SCA

Is CVE-2023-37544 in your dependencies?

O3 detects CVE-2023-37544 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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