VYPR
Medium severity4.8NVD Advisory· Published Feb 23, 2021· Updated Jun 17, 2026

CVE-2021-20220

CVE-2021-20220

Description

A flaw was found in Undertow. A regression in the fix for CVE-2020-10687 was found. HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own. The highest threat from this vulnerability is to data confidentiality and integrity.

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Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
io.undertow:undertow-coreMaven
>= 2.1.0, < 2.1.62.1.6
io.undertow:undertow-coreMaven
< 2.0.342.0.34

Affected products

2

Patches

Vulnerability mechanics

References

6

News mentions

0

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