CVE-2022-33684 Apache Pulsar Disabled Certificate Validation for OAuth Client Credential Requests makes C++/Python Clients vulnerable to MITM attack

What is CVE-2022-33684?

CVE-2022-33684 is a high-severity vulnerability in Apache Pulsar, published on 4 Nov 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The Apache Pulsar C++ Client does not verify peer TLS certificates when making HTTPS calls for the OAuth2.0 Client Credential Flow, even when tlsAllowInsecureConnection is disabled via configuration. This vulnerability allows an attacker to perform a man in the middle attack and intercept and/or modify the GET request that is sent to the ClientCredentialFlow 'issuer url'. The intercepted credentials can be used to acquire authentication data from the OAuth2.0 server to then authenticate with an Apache Pulsar cluster. 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. The Apache Pulsar Python Client wraps the C++ client, so it is also vulnerable in the same way. This issue affects Apache Pulsar C++ Client and Python 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 to 2.10.1; 2.6.4 and earlier. Any users running affected versions of the C++ Client or the Python Client should rotate vulnerable OAuth2.0 credentials, including client_id and client_secret. 2.7 C++ and Python Client users should upgrade to 2.7.5 and rotate vulnerable OAuth2.0 credentials. 2.8 C++ and Python Client users should upgrade to 2.8.4 and rotate vulnerable OAuth2.0 credentials. 2.9 C++ and Python Client users should upgrade to 2.9.3 and rotate vulnerable OAuth2.0 credentials. 2.10 C++ and Python Client users should upgrade to 2.10.2 and rotate vulnerable OAuth2.0 credentials. 3.0 C++ users are unaffected and 3.0 Python Client users will be unaffected when it is released. Any users running the C++ and Python Client for 2.6 or less should upgrade to one of the above patched versions.

Weakness: CWE-295

Which versions are affected by CVE-2022-33684?

9 open source packages ship an affected version, including pulsar-client. It affects 1 product.

Products include Apache Pulsar.

How do I fix CVE-2022-33684?

Upgrade pulsar-client to a fixed version for your release line: 2.7.5, 2.8.4, 2.9.3 or 2.10.2.

Is CVE-2022-33684 being exploited?

There is no known exploitation of CVE-2022-33684 in the wild and no public exploit code.

Other vulnerabilities in Apache Pulsar

• CVE-2021-22160 Authentication with JWT allows use of “none”-algorithm Critical 9.8
• CVE-2023-30429 Apache Pulsar: Incorrect Authorization for Function Worker when using mTLS Authentication through Pulsar Proxy Critical 9.6
• CVE-2024-27135 Apache Pulsar: Improper Input Validation in Pulsar Function Worker allows Remote Code Execution High 8.5
• CVE-2024-27894 Apache Pulsar: Pulsar Functions Worker Allows Unauthorized File Access and Unauthorized HTTP/HTTPS Proxying High 8.5
• CVE-2024-27317 Apache Pulsar: Pulsar Functions Worker's Archive Extraction Vulnerability Allows Unauthorized File Modification High 8.4

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-5r3h-c3r7-9w4h, PYSEC-2026-901.