Summary
Apache Pulsar Java Client vulnerable to Improper Certificate Validation
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.
Impact
CVE-2022-33681 has a CVSS score of 5.9 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.7.5, 2.8.4, 2.9.3, 2.10.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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org.apache.pulsar:pulsar-client to 2.7.5 or later; org.apache.pulsar:pulsar-client to 2.8.4 or later; org.apache.pulsar:pulsar-client to 2.9.3 or later; org.apache.pulsar:pulsar-client to 2.10.1 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2022-33681? CVE-2022-33681 is a medium-severity security vulnerability in org.apache.pulsar:pulsar-client (maven), affecting versions < 2.7.5. It is fixed in 2.7.5, 2.8.4, 2.9.3, 2.10.1.
- How severe is CVE-2022-33681? CVE-2022-33681 has a CVSS score of 5.9 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.apache.pulsar:pulsar-client are affected by CVE-2022-33681? org.apache.pulsar:pulsar-client (maven) versions < 2.7.5 is affected.
- Is there a fix for CVE-2022-33681? Yes. CVE-2022-33681 is fixed in 2.7.5, 2.8.4, 2.9.3, 2.10.1. Upgrade to this version or later.
- Is CVE-2022-33681 exploitable, and should I be worried? Whether CVE-2022-33681 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2022-33681 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2022-33681?
- Upgrade
org.apache.pulsar:pulsar-clientto 2.7.5 or later - Upgrade
org.apache.pulsar:pulsar-clientto 2.8.4 or later - Upgrade
org.apache.pulsar:pulsar-clientto 2.9.3 or later - Upgrade
org.apache.pulsar:pulsar-clientto 2.10.1 or later
- Upgrade