CVE-2023-37544
HIGHCVE-2023-37544 is a high-severity (CVSS 7.5) Improper Authentication vulnerability in org.apache.pulsar:pulsar-websocket. O3 Security confirms whether CVE-2023-37544 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Apache Pulsar WebSocket Proxy: Improper Authentication for WebSocket Proxy Endpoint Allows DoS
Blast Radius
org.apache.pulsar:pulsar-websocket☕org.apache.pulsar:pulsar-websocket☕org.apache.pulsar:pulsar-websocketReal-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
| 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 dependencyDetect
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
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.