CVE-2021-21409
Description
A flaw was found in Netty. There is an issue where the content-length header is not validated correctly if the request uses a single Http2HeaderFrame with the endstream set to true. This flaw leads to request smuggling if the request is proxied to a remote peer and translated to HTTP/1.1. The highest threat from this vulnerability is to integrity.
Statement
Red Hat Satellite ships a vulnerable Netty version embedded in Candlepin. However, it is not directly vulnerable since the HTTP requests are handled by Tomcat and not by Netty. Red Hat OpenStack Platform's OpenDaylight will not be updated for this flaw because it was deprecated as of OpenStack Platform 14 and is only receiving security fixes for Important and Critical flaws.
In OpenShift Container Platform (OCP), the Hive/Presto/Hadoop components that comprise the OCP Metering stack, ship the vulnerable version of netty-codec-http package. Since the release of OCP 4.6, the Metering product has been deprecated [1], hence the affected components are marked as wontfix. This may be fixed in the future.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | 5.9 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | High | High | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Understanding the Weakness (CWE)
Integrity,Non-Repudiation,Access Control
Technical Impact: Unexpected State; Hide Activities; Bypass Protection Mechanism
An attacker could create HTTP messages to exploit a number of weaknesses including 1) the message can trick the web server to associate a URL with another URL's webpage and caching the contents of the webpage (web cache poisoning attack), 2) the message can be structured to bypass the firewall protection mechanisms and gain unauthorized access to a web application, and 3) the message can invoke a script or a page that returns client credentials (similar to a Cross Site Scripting attack).
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