CVE-2019-17569
Description
The refactoring in 9.0.28 introduced a regression. The result of the regression was that invalid Transfer-Encoding headers were incorrectly processed leading to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.
It affects the versions of Apache Tomcat 9 (9.0.28 to 9.0.30), Tomcat 8 (8.5.48 to 8.5.50), and Tomcat 7 (7.0.98 to 7.0.99).
Statement
This flaw did not affect the versions of Tomcat as shipped with Red Enterprise Linux 5, 6, 7 and 8, as they did not include the vulnerable code, which was introduced in a later version of the package.
OpenDaylight in Red Hat OpenStack 10 & 13 was in technical preview status, because of this no fixes will be released for it.
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 | 4.3 | 4.8 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | High | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | Required | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | Low | N/A |
| Integrity Impact | None | Low | N/A |
| Availability Impact | Low | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/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).
Acknowledgements
Red Hat would like to thank @ZeddYu (Apache Tomcat Security Team) for reporting this issue.
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