CVE-2020-27782

Name: CVE-2020-27782
Creator: NVD / NIST
Published: 2021-02-23T19:15:13.15+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.27%

Last modified Jun 17, 2026

CVE-2020-27782 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 1.27% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

1.27%

66.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions	Update
Redhat	Jboss Fuse	6.0.0	—
Redhat	Jboss Fuse	7.0.0	—
Redhat	Openshift Application Runtimes	All versions	—
Redhat	Undertow	2.0.33	Sp2
Redhat	Undertow	2.1.5	Sp1
Redhat	Undertow	2.2.3	Sp1

References

https://bugzilla.redhat.com/show_bug.cgi?id=1901304Issue Tracking, Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1901304Issue Tracking, Vendor Advisory

Timeline

Published: Feb 23, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-27782?

How severe is CVE-2020-27782?

CVE-2020-27782 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.27% probability of exploitation in the next 30 days.

How do I fix CVE-2020-27782?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-27782?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST