CVE-2022-34321

Improper Authentication vulnerability in Apache Pulsar Proxy allows an attacker to connect to the /proxy-stats endpoint without authentication. The vulnerable endpoint exposes detailed statistics about live connections, along with the capability to modify the logging level of proxied connections without requiring proper authentication credentials.

This issue affects Apache Pulsar versions from 2.6.0 to 2.10.5, from 2.11.0 to 2.11.2, from 3.0.0 to 3.0.1, and 3.1.0.

The known risks include exposing sensitive information such as connected client IP and unauthorized logging level manipulation which could lead to a denial-of-service condition by significantly increasing the proxys logging overhead. When deployed via the Apache Pulsar Helm chart within Kubernetes environments, the actual client IP might not be revealed through the load balancers default behavior, which typically obscures the original source IP addresses when externalTrafficPolicy is being configured to Cluster by default. The /proxy-stats endpoint contains topic level statistics, however, in the default configuration, the topic level statistics arent known to be exposed.

2.10 Pulsar Proxy users should upgrade to at least 2.10.6. 2.11 Pulsar Proxy users should upgrade to at least 2.11.3. 3.0 Pulsar Proxy users should upgrade to at least 3.0.2. 3.1 Pulsar Proxy users should upgrade to at least 3.1.1.

Users operating versions prior to those listed above should upgrade to the aforementioned patched versions or newer versions. Additionally, its imperative to recognize that the Apache Pulsar Proxy is not intended for direct exposure to the internet. The architectural design of Pulsar Proxy assumes that it will operate within a secured network environment, safeguarded by appropriate perimeter defenses.

Weakness

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

Extended Description

As data is migrated to the cloud, if access does not require authentication, it can be easier for attackers to access the data from anywhere on the Internet.

Potential Mitigations

• Divide the software into anonymous, normal, privileged, and administrative areas. Identify which of these areas require a proven user identity, and use a centralized authentication capability.
• Identify all potential communication channels, or other means of interaction with the software, to ensure that all channels are appropriately protected. Developers sometimes perform authentication at the primary channel, but open up a secondary channel that is assumed to be private. For example, a login mechanism may be listening on one network port, but after successful authentication, it may open up a second port where it waits for the connection, but avoids authentication because it assumes that only the authenticated party will connect to the port.
• In general, if the software or protocol allows a single session or user state to persist across multiple connections or channels, authentication and appropriate credential management need to be used throughout.
• Where possible, avoid implementing custom authentication routines and consider using authentication capabilities as provided by the surrounding framework, operating system, or environment. These may make it easier to provide a clear separation between authentication tasks and authorization tasks.
• In environments such as the World Wide Web, the line between authentication and authorization is sometimes blurred. If custom authentication routines are required instead of those provided by the server, then these routines must be applied to every single page, since these pages could be requested directly.
• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator [REF-45].

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/12.html
• https://cwe.mitre.org/data/definitions/166.html
• https://cwe.mitre.org/data/definitions/216.html
• https://cwe.mitre.org/data/definitions/36.html
• https://cwe.mitre.org/data/definitions/62.html

References

• https://lists.apache.org/thread/ods5tq2hpl390hvjnvxv0bcg4rfpgjj8
• https://pulsar.apache.org/security/CVE-2022-34321/