Inconsistent interpretation of HTTP requests in Undertow - CVE-2021-20220
Published: March 17, 2021
Vulnerability identifier: #VU51518
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-20220
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to preform HTTP request smuggling attacks.
The vulnerability exists due to improper validation of HTTP requests when processing HTTP/1.x and HTTP/2 protocols. A remote attacker can send a specially crafted HTTP request to the server and smuggle arbitrary HTTP headers.
Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.
Affected software
Undertow
JBoss Enterprise Application Platform
Red Hat Single Sign-On
JBoss Enterprise Application Platform
Red Hat Single Sign-On
How to mitigate CVE-2021-20220
Install updates from vendor's website.
Undertow - addressed in versions 2.0.34, 2.1.6, 2.2.0
JBoss Enterprise Application Platform - update to 7.3.6
Red Hat Single Sign-On - update to 7.4.6
JBoss Enterprise Application Platform - update to 7.3.6
Red Hat Single Sign-On - update to 7.4.6