CVE-2022-33681 | Improper Hostname Verification in Java Client and Proxy can expose authentication data via MITM

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 authentication data could be exposed to an attacker. An attacker can only take advantage of this vulnerability by taking control of a machine 'between' the client and the server. The attacker must then actively manipulate traffic to perform the attack by providing the client with a cryptographically valid certificate for an unrelated host. Because the client sends authentication data before performing hostname verification, an attacker could gain access to the client’s authentication data. The client eventually closes the connection when it verifies the hostname and identifies the targeted hostname does not match a hostname on the certificate. Because the client eventually closes the connection, the value of the intercepted authentication data depends on the authentication method used by the client. Token based authentication and username/password authentication methods are vulnerable because the authentication data can be used to impersonate the client in a separate session. This issue affects Apache Pulsar Java Client versions 2.7.0 to 2.7.4; 2.8.0 to 2.8.3; 2.9.0 to 2.9.2; 2.10.0; 2.6.4 and earlier.

Published: 2022-09-23 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-33681 is rated Low Risk (38.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.56%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-33681

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.18% 0.56% +0.39%
2 2026-05-09 0.08% 0.18% +0.10%
3 2025-11-21 — 0.08% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-33681

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2022-33681

GitHub Security Advisory for CVE-2022-33681

GHSA-c5fp-x2h5-vjv7 · Severity: medium · Ecosystem: maven — Apache Pulsar Java Client vulnerable to Improper Certificate Validation

OS Trackers for CVE-2022-33681

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2022-33681

Affected software / configurations for CVE-2022-33681

Vendor Product Version Raw CPE
apache pulsar < 2.7.5 cpe:2.3:a:apache:pulsar:*:*:*:*:*:*:*:*
apache pulsar >= 2.8.0, < 2.8.4 cpe:2.3:a:apache:pulsar:*:*:*:*:*:*:*:*
apache pulsar >= 2.9.0, < 2.9.3 cpe:2.3:a:apache:pulsar:*:*:*:*:*:*:*:*
apache pulsar 2.10.0 cpe:2.3:a:apache:pulsar:2.10.0:-:*:*:*:*:*:*

References for CVE-2022-33681

cvelogic Threat Intelligence