Off-by-one Error Affecting nginx package, versions <1.18.0-6.1


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

Exploit Maturity
Proof of Concept
EPSS
53.46% (99th percentile)

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  • Snyk IDSNYK-ECHOLATEST-NGINX-18011597
  • published18 Jul 2026
  • disclosed1 Jun 2021

Introduced: 1 Jun 2021

CVE-2021-23017  (opens in a new tab)
CWE-193  (opens in a new tab)

How to fix?

Upgrade Echo:latest nginx to version 1.18.0-6.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nginx package and not the nginx package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cause 1-byte memory overwrite, resulting in worker process crash or potential other impact.

References

CVSS Base Scores

version 3.1