How severe is CVE-2021-41571?

CVE-2021-41571 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-41571 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-41571?

CVE-2021-41571 primarily affects Apache Pulsar. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-41571?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-41571 published?

CVE-2021-41571 was published on 2022-02-01 and last updated on 2026-06-17.

CVE-2021-41571

CVE-2021-41571 is a medium-severity vulnerability in Apache Pulsar with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Apache Pulsar
Published: 2022-02-01
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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.
How severe is CVE-2021-41571?: CVE-2021-41571 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-41571 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-41571?: CVE-2021-41571 primarily affects Apache Pulsar. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-41571?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-41571 published?: CVE-2021-41571 was published on 2022-02-01 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:apache:pulsar:*:*:*:*:*:*:*:*
cpe:2.3:a:apache:pulsar:2.8.0:*:*:*:*:*:*:*

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