CVE-2019-18802: Critical severity envoy proxy vulnerability
An issue was discovered in Envoy 1.12.0. An untrusted remote client may send an HTTP header (such as Host) with whitespace after the header content. Envoy will treat "header-value " as a different string from "header-value" so for example with the Host header "example.com " one could bypass "example.com" matchers.
Other sources
Malformed request header may cause route matchers or access controls to be bypassed, resulting in escalation of privileges or information disclosure.
— Red Hat
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is CVE-2019-18802?
CVE-2019-18802 is a vulnerability discovered in Envoy 1.12.0 that allows an untrusted remote client to send an HTTP header with whitespace after the header content.
How can an untrusted remote client exploit CVE-2019-18802?
An untrusted remote client can exploit CVE-2019-18802 by sending an HTTP header with whitespace after the header content, which may result in bypassing certain security measures.
What is the severity of CVE-2019-18802?
The severity of CVE-2019-18802 is critical with a score of 9.8.
How can I fix CVE-2019-18802?
To fix CVE-2019-18802, upgrade to Envoy version 1.12.1 or later.
Where can I find more information about CVE-2019-18802?
You can find more information about CVE-2019-18802 on the Envoy mailing list, GitHub security advisories, and Red Hat security advisories.