What is CVE-2021-43045?

CVE-2021-43045 is a high-severity vulnerability in Apache Avro, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2022-01-06.

How severe is CVE-2021-43045?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Apache Avro

CVE-2021-43045

A vulnerability in the .NET SDK of Apache Avro allows an attacker to allocate excessive resources, potentially causing a denial-of-service attack. This issue affects .NET applications using Apache Avro version 1.10.2 and prior versions. Users should update to version 1.11.0 which addresses this issue.

Published 2022-01-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.030 (86.7th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 86.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.030 · newest: 0.030 · change: 0.000

Affected products

Apache Avro
Apache Software Foundation Avro — versions Apache Avro

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

lists.apache.org/thread/5fttw9vk6gd2p3b846nox7hcj5469xfd (Mailing List, Vendor Advisory)
www.openwall.com/lists/oss-security/2022/01/06/8 (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-43045?: CVE-2021-43045 is a high-severity vulnerability in Apache Avro, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2022-01-06.
How severe is CVE-2021-43045?: High severity. CVSS v3 base score is 7.5 out of 10.