A flaw was found in the Undertow AJP connector. Malicious requests and abrupt connection closes could be triggered by an attacker using query strings with non-RFC compliant characters resulting in a denial of service. The highest threat from this vulnerability is to system availability. This affects Undertow 2.1.5.SP1, 2.0.33.SP2, and 2.2.3.SP1.

Affected Packages

Maven io.undertow:undertow-core

Affected versions: 2.1.0 (fixed in 2.1.5)

Maven io.undertow:undertow-core

Affected versions: 0 (fixed in 2.0.33)

Related CVEs

CVE-2020-27782

Key Information

GHSA ID

GHSA-rhcw-wjcm-9h6g

Published

February 9, 2022 12:54 AM

Last Modified

March 31, 2021 11:48 PM

CVSS Score

7.5 /10

Primary Ecosystem

Maven

Primary Package

io.undertow:undertow-core

GitHub Reviewed

✓ Yes

Dataset

Last updated: August 3, 2025 6:48 AM

Data from GitHub Advisory Database. This information is provided for research and educational purposes.