CVE-2022-33681Network attack vector

Authentication-data exposure via delayed hostname verification

Published Sep 23, 2022 · Updated May 22, 2025

Improper certificate validation in Apache Pulsar Java Client and Proxy allows man-in-the-middle attackers to read authentication data. The client sends credentials before confirming that the server certificate matches the requested hostname, then closes the mismatched connection only afterward. The attacker must control an intervening machine and present a valid certificate for another host; exposed tokens or passwords support client impersonation.

CVSS severity5.9
Medium
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in Apache Pulsar Java Client and Proxy allows man-in-the-middle attackers to read authentication data. The client sends credentials before confirming that the server certificate matches the requested hostname, then closes the mismatched connection only afterward. The attacker must control an intervening machine and present a valid certificate for another host; exposed tokens or passwords support client impersonation.

The record

CVE
CVE-2022-33681
Published
Sep 23, 2022
Updated
May 22, 2025
Vendor
The Apache Software Foundation
Product
Apache Pulsar
Classifications
CWE-295, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 23, 2022CVE publishedPublication date reported by the CVE source.
  2. May 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.10.0
  2. Affected versionversion=2.6 and earlier <=2.6.4
  3. Affected versionversion=2.7 <=2.7.4
  4. Affected versionversion=2.8 <=2.8.3
  5. Affected versionversion=2.9 <=2.9.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Pulsarversion=2.10.0; version=2.6 and earlier <=2.6.4; version=2.7 <=2.7.4; version=2.8 <=2.8.3; version=2.9 <=2.9.2

Published CVSS scores

5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
5.9CISA-ADPCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-295Improper Certificate Validation
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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