What is CVE-2021-42010?

CVE-2021-42010 is a critical-severity vulnerability in Apache Heron, classified under Improper Encoding or Escaping of Output. CVSS score: 9.8/10. Published 2022-10-24.

How severe is CVE-2021-42010?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Apache Heron

CVE-2021-42010

Heron versions <= 0.20.4-incubating allows CRLF log injection because of the lack of escaping in the log statements. Please update to version 0.20.5-incubating which addresses this issue.

Published 2022-10-24 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.016 (74.6th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 74.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: +0.000

Affected products

Apache Heron
Apache Software Foundation Heron (Incubating) — versions Apache Heron 0.20.4-incubating

Weakness classification (CWE)

CWE-116 — Improper Encoding or Escaping of Output

References

lists.apache.org/thread/j65nwr8n7jchngwqptzh100drcr4ry2q (Mailing List, Vendor Advisory)
www.openwall.com/lists/oss-security/2022/10/23/2 (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-42010?: CVE-2021-42010 is a critical-severity vulnerability in Apache Heron, classified under Improper Encoding or Escaping of Output. CVSS score: 9.8/10. Published 2022-10-24.
How severe is CVE-2021-42010?: Critical severity. CVSS v3 base score is 9.8 out of 10.