CVE-2022-33681 — Delayed TLS hostname verification in the Pulsar Java Client and the Pulsar Proxy

Delayed TLS hostname verification in the Pulsar Java Client and the Pulsar Proxy make each client vulnerable to a man in the middle attack. Connections from the Pulsar Java Client to the Pulsar Broker/Proxy and connections from the Pulsar Proxy to the Pulsar Broker are vulnerable

01What is this vulnerability?

Delayed TLS hostname verification in the Pulsar Java Client and the Pulsar Proxy make each client vulnerable to a man in the middle attack. Connections from the Pulsar Java Client to the Pulsar Broker/Proxy and connections from the Pulsar Proxy to the Pulsar Broker are vulnerable. Authentication data is sent before verifying the server’s TLS certificate matches the hostname, which means…

02Affected products

Vendor	Product	Versions
Apache Software Foundation	Apache Pulsar	2.10.0, 2.7, 2.8, 2.9, 2.6 and earlier

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2022-09-23T09:25:13.000Z
• Last modified: 2025-05-22T20:37:29.107Z

09References

• lists.apache.org — https://lists.apache.org/thread/fpo6x10trvn20hlk0dmnr5vlz5v4kl3d