CVE-2021-41571

Public Exploit
Pulsar Admin API allows access to data from other tenants using getMessageById API

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.

Remediation

Workaround:

  • If you are running Pulsar behind a proxy you can disable access to the REST API for the flawed API /admin/v2/non-persistent/{tenant}/{namespace}/{topic}/ledger/{ledgerId}/entry/{entryId}

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.98% Top 25%
Vendor Advisory apache.org Vendor Advisory apache.org
Affected: Apache Software Foundation Apache Pulsar
Published at:
Updated at:

References

Link Tags
https://pulsar.apache.org/admin-rest-api/#operation/getLastMessageId patch vendor advisory
https://github.com/apache/pulsar/issues/11814 patch exploit third party advisory issue tracking
https://lists.apache.org/thread/8n3k7pvyh4cf9q2jfzb6pb32ync6xlvr vendor advisory mailing list

Frequently Asked Questions

What is the severity of CVE-2021-41571?
CVE-2021-41571 has been scored as a medium severity vulnerability.
How to fix CVE-2021-41571?
As a workaround for remediating CVE-2021-41571: If you are running Pulsar behind a proxy you can disable access to the REST API for the flawed API /admin/v2/non-persistent/{tenant}/{namespace}/{topic}/ledger/{ledgerId}/entry/{entryId}
Is CVE-2021-41571 being actively exploited in the wild?
It is possible that CVE-2021-41571 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-41571?
CVE-2021-41571 affects Apache Software Foundation Apache Pulsar.
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