Vulnerability · Published Jul 12, 2021 · Assigned by apache

CVE-2021-33037Incorrect Transfer-Encoding handling with HTTP/1.0

Medium 5.3

In plain English

A medium-severity security flaw in Apache Tomcat from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 74.7% (higher than 99.5% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.3Medium

Exploit odds (30 days)74.7%top 0.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Apache Tomcat 10.0.0-M1 to 10.0.6, 9.0.0.M1 to 9.0.46 and 8.5.0 to 8.5.66 did not correctly parse the HTTP transfer-encoding request header in some circumstances leading to the possibility to request smuggling when used with a reverse proxy. Specifically: - Tomcat incorrectly ignored the transfer encoding header if the client declared it would only accept an HTTP/1.0 response; - Tomcat honoured the identify encoding; and - Tomcat did not ensure that, if present, the chunked encoding was the final encoding.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	tomcat9	9.0.43-2	DEBIAN-CVE-2021-33037
Debian:13	tomcat9	9.0.43-2	DEBIAN-CVE-2021-33037
Debian:14	tomcat9	9.0.43-2	DEBIAN-CVE-2021-33037
Maven	org.apache.tomcat:tomcat	10.0.7	GHSA-4vww-mc66-62m6
Maven	org.apache.tomcat:tomcat	9.0.48	GHSA-4vww-mc66-62m6
Maven	org.apache.tomcat:tomcat	8.5.68	GHSA-4vww-mc66-62m6

Affected products (as reported)

Vendor	Product	Versions
Apache Software Foundation	Apache Tomcat	Apache Tomcat 10 10.0.0-M1 to 10.0.6Apache Tomcat 9 9.0.0.M1 to 9.0.46Apache Tomcat 8 8.5.0 to 8.5.66

Weakness: CWE-444

References

https://lists.apache.org/thread.html/r612a79269b0d5e5780c62dfd34286a8037232fec0bc6f1a7e60c9381%40%3Cannounce.tomcat.apache.org%3E x_refsource_MISC
https://www.oracle.com//security-alerts/cpujul2021.html x_refsource_MISC
[tomee-commits] 20210728 [jira] [Created] (TOMEE-3778) Update embedded Tomcat to 9.0.48 or later to address CVE-2021-33037 mailing-list, x_refsource_MLIST
[tomee-commits] 20210728 [jira] [Commented] (TOMEE-3778) Update embedded Tomcat to 9.0.48 or later to address CVE-2021-33037 mailing-list, x_refsource_MLIST
[debian-lts-announce] 20210805 [SECURITY] [DLA 2733-1] tomcat8 security update mailing-list, x_refsource_MLIST
DSA-4952 vendor-advisory, x_refsource_DEBIAN
[tomee-commits] 20210830 [jira] [Commented] (TOMEE-3778) Update embedded Tomcat to 9.0.48 or later to address CVE-2021-33037 mailing-list, x_refsource_MLIST
[tomee-commits] 20210913 [jira] [Commented] (TOMEE-3778) Update embedded Tomcat to 9.0.48 or later to address CVE-2021-33037 mailing-list, x_refsource_MLIST
[tomee-commits] 20210914 [jira] [Commented] (TOMEE-3778) Update embedded Tomcat to 9.0.48 or later to address CVE-2021-33037 mailing-list, x_refsource_MLIST
[tomee-commits] 20210916 [jira] [Resolved] (TOMEE-3778) Update embedded Tomcat to 9.0.48 or later to address CVE-2021-33037 mailing-list, x_refsource_MLIST
https://www.oracle.com/security-alerts/cpuoct2021.html x_refsource_MISC
https://security.netapp.com/advisory/ntap-20210827-0007/ x_refsource_CONFIRM
https://kc.mcafee.com/corporate/index?page=content&id=SB10366 x_refsource_CONFIRM
https://www.oracle.com/security-alerts/cpujan2022.html x_refsource_MISC
https://www.oracle.com/security-alerts/cpuapr2022.html x_refsource_MISC
GLSA-202208-34 vendor-advisory, x_refsource_GENTOO