Auth bypass in Apache Pulsar

CVE-2021-41571

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.

Vulnerability class: Broken Access Control

EPSS: 0.017 (75.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-41571?
CVE-2021-41571 is a medium-severity vulnerability in Apache Pulsar, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2022-02-01.
How severe is CVE-2021-41571?
Medium severity. CVSS v3 base score is 6.5 out of 10.