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PulsarApplication · Apache

CVE-2022-33681

MEDIUM · 5.9 CVSS v3.1 Published 2022-09-23
Fix available
A fix is available. Upgrade to 2.7.5 / 2.8.4 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The Pulsar Java Client sends authentication data (tokens or username/password) to the server BEFORE performing TLS hostname verification. This means a MITM attacker positioned between client and server can intercept authentication credentials before the client detects the certificate hostname mismatch and closes the connection. The vulnerability affects client-to-broker and proxy-to-broker connections.

MitigationUpgrade Apache Pulsar Java Client to version 2.7.5, 2.8.4, 2.9.3, 2.10.1, or 2.11.0 or later, which implements hostname verification before sending authentication data.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
PulsarApplication
Affected:< 2.7.5>= 2.8.0, < 2.8.4>= 2.9.0, < 2.9.3= 2.10.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Pulsar Java Client version
    Locate the pulsar-client-core jar or check Maven dependency: mvn dependency:tree | grep pulsar-client-core. Also check broker/admin version via 'pulsar-admin versions' or the admin API /admin/v2/schema/pulsar/version
    Affected if Version is < 2.7.5, >= 2.8.0 and < 2.8.4, >= 2.9.0 and < 2.9.3, or exactly 2.10.0
  2. Confirm TLS/SSL is enabled for client connections
    Review client configuration files (client.conf) or YAML configs for 'tlsEnabled' or 'tlsTrustCertsFilePath' settings under brokerServicePortTLS or webServicePortTLS. Check broker.conf for 'webServicePortTLS' and 'brokerServicePortTLS' values
    Affected if TLS is enabled (ports 8443, 6651) - the vulnerability only applies when TLS is used because it involves hostname verification during TLS handshake
  3. Check client-to-broker TLS configuration
    Inspect client connection code or config for 'serviceUrl' using 'pulsar+ssl://' or 'pulsar://' with TLS trust store configured. Look for 'tlsTrustCertsFilePath' or 'tlsTrustStorePassword' in client properties
    Affected if Client connects to broker using TLS (pulsar+ssl:// or pulsar:// with TLS settings)
  4. Verify proxy-to-broker TLS configuration
    Check proxy.conf or proxy YAML for 'proxyToBroker' TLS settings. Look for 'tlsTrustCertsFilePath', 'tlsKeyFilePath', 'tlsCertificateFilePath' under proxy configuration sections
    Affected if Proxy is configured with TLS to connect to brokers - the vulnerability affects proxy-to-broker connections
  5. Identify authentication mechanism in use
    Review authentication configuration in broker.conf (authenticateThrottleRate, authenticationEnabled, authenticationProviders) and client configs. Look for 'authentication' or 'authPlugin' settings
    Affected if Authentication is enabled using token-based (JWT) or username/password authentication - unauthenticated connections are not affected by this credential interception issue

You are affected if you use a vulnerable Pulsar Java Client version (2.7.x before 2.7.5, 2.8.0-2.8.3, 2.9.0-2.9.2, or 2.10.0) with TLS-enabled client-to-broker or proxy-to-broker connections using token or username/password authentication.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.7.5 / 2.8.4 / 2.9.3 or later
Fixed in 2.7.52.8.42.9.3
Interim mitigation

Upgrade Apache Pulsar Java Client to version 2.7.5, 2.8.4, 2.9.3, 2.10.1, or 2.11.0 or later, which implements hostname verification before sending authentication data.

Recommended fix High confidence

Upgrade to Pulsar 2.7.5, 2.8.4, 2.9.3, or 2.10.1+ (choose the nearest minor version upgrade)

  1. Upgrade Apache Pulsar Java Client to a fixed version: 2.7.5, 2.8.4, 2.9.3, or 2.10.1 or later
  2. If using Pulsar Proxy, ensure the Proxy component is also upgraded to the same fixed version to protect broker connections
  3. After upgrade, verify TLS connections are properly validating hostname before sending authentication data
  4. Test in staging environment before production deployment
Caveat No breaking changes expected; this is a security fix that corrects TLS handshake ordering

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Pulsar Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,880
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-33681 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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