Incorrect Transfer-Encoding handling with HTTP/1.0

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2021-33037
StatePUBLISHED
Assignerapache
Source PriorityCVE Program / NVD first with legacy fallback
Published2021-07-12 15:15:08 UTC
Updated2026-08-25 16:28:27 UTC
DescriptionApache 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.

Risk And Classification

Primary CVSS: v3.1 5.3 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS: 0.753530000 probability, percentile 0.994750000 (date 2026-08-25)

Problem Types: CWE-444 | CWE-444 CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
2.0[email protected]Primary5AV:N/AC:L/Au:N/C:N/I:P/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS v2.0 Breakdown

Access Vector
Network
Access Complexity
Low
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None

AV:N/AC:L/Au:N/C:N/I:P/A:N

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Apache Tomcat All All All All
Application Apache Tomcat All All All All
Application Apache Tomcat All All All All
Application Apache Tomee 8.0.6 All All All
Operating System Debian Debian Linux 10.0 All All All
Operating System Debian Debian Linux 9.0 All All All
Application Mcafee Epolicy Orchestrator All All All All
Application Mcafee Epolicy Orchestrator 5.10.0 - All All
Application Mcafee Epolicy Orchestrator 5.10.0 update_1 All All
Application Mcafee Epolicy Orchestrator 5.10.0 update_10 All All
Application Mcafee Epolicy Orchestrator 5.10.0 update_2 All All
Application Mcafee Epolicy Orchestrator 5.10.0 update_3 All All
Application Mcafee Epolicy Orchestrator 5.10.0 update_4 All All
Application Mcafee Epolicy Orchestrator 5.10.0 update_5 All All
Application Mcafee Epolicy Orchestrator 5.10.0 update_6 All All
Application Mcafee Epolicy Orchestrator 5.10.0 update_7 All All
Application Mcafee Epolicy Orchestrator 5.10.0 update_8 All All
Application Mcafee Epolicy Orchestrator 5.10.0 update_9 All All
Application Oracle Agile Product Lifecycle Management 9.3.6 All All All
Application Oracle Communications Cloud Native Core Policy 1.14.0 All All All
Application Oracle Communications Cloud Native Core Service Communication Proxy 1.14.0 All All All
Application Oracle Communications Diameter Signaling Router All All All All
Application Oracle Communications Instant Messaging Server 10.0.1.5.0 All All All
Application Oracle Communications Policy Management 12.5.0 All All All
Application Oracle Communications Pricing Design Center 12.0.0.3.0 All All All
Application Oracle Communications Session Report Manager All All All All
Application Oracle Communications Session Route Manager All All All All
Application Oracle Graph Server And Client All All All All
Application Oracle Healthcare Translational Research 4.1.0 All All All
Application Oracle Hospitality Cruise Shipboard Property Management System 20.1.0 All All All
Application Oracle Instantis Enterprisetrack 17.1 All All All
Application Oracle Instantis Enterprisetrack 17.2 All All All
Application Oracle Instantis Enterprisetrack 17.3 All All All
Application Oracle Managed File Transfer 12.2.1.3.0 All All All
Application Oracle Managed File Transfer 12.2.1.4.0 All All All
Application Oracle Mysql Enterprise Monitor All All All All
Application Oracle Sd-wan Edge 9.0 All All All
Application Oracle Sd-wan Edge 9.1 All All All
Application Oracle Secure Global Desktop 5.6 All All All
Application Oracle Utilities Testing Accelerator 6.0.0.1.1 All All All
Application Oracle Utilities Testing Accelerator 6.0.0.2.2 All All All
Application Oracle Utilities Testing Accelerator 6.0.0.3.1 All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 10 10.0.0-M1 to 10.0.6 Not specified
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 9 9.0.0.M1 to 9.0.46 Not specified
CNA Apache Software Foundation Apache Tomcat affected Apache Tomcat 8 8.5.0 to 8.5.66 Not specified

References

ReferenceSourceLinkTags
lists.apache.org/thread.html/rf1b54fd3f52f998ca4829159a88cc4c23d6cef5c6447d009... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Oracle Critical Patch Update Advisory - April 2022 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Pony Mail! af854a3a-2127-422b-91ae-364da2661108 lists.apache.org Mailing List, Vendor Advisory
lists.apache.org/thread.html/rd0dfea39829bc0606c936a16f6fca338127c86c0a1083970... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Oracle Critical Patch Update Advisory - October 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
Security Bulletin - ePolicy Orchestrator update addresses two product vulnerabilities (CVE-2021-31834 and CVE-2021-31835) and updates Java, OpenSSL, and Tomcat af854a3a-2127-422b-91ae-364da2661108 kc.mcafee.com Third Party Advisory
Oracle Critical Patch Update Advisory - July 2021 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
[SECURITY] [DLA 2733-1] tomcat8 security update af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Mailing List, Third Party Advisory
lists.apache.org/thread.html/r290aee55b72811fd19e75ac80f6143716c079170c5671b96... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
July 2021 Apache Tomcat Vulnerabilities in NetApp Products | NetApp Product Security af854a3a-2127-422b-91ae-364da2661108 security.netapp.com Third Party Advisory
lists.apache.org/thread.html/rc6ef52453bb996a98cb45442871a1db56b7c349939e45d82... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Oracle Critical Patch Update Advisory - January 2022 af854a3a-2127-422b-91ae-364da2661108 www.oracle.com Patch, Third Party Advisory
lists.apache.org/thread.html/re01e7e93154e8bdf78a11a23f9686427bd3d51fc6e12c508... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
lists.apache.org/thread.html/r40f921575aee8d7d34e53182f862c45cbb8f3d898c9d4e86... af854a3a-2127-422b-91ae-364da2661108 lists.apache.org
Apache Tomcat: Multiple Vulnerabilities (GLSA 202208-34) — Gentoo security af854a3a-2127-422b-91ae-364da2661108 security.gentoo.org Third Party Advisory
Debian -- Security Information -- DSA-4952-1 tomcat9 af854a3a-2127-422b-91ae-364da2661108 www.debian.org Third Party Advisory
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
Pony Mail! MITRE lists.apache.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: The Apache Tomcat Security Team would like to thank Bahruz Jabiyev, Steven Sprecher and Kaan Onarlioglu of NEU seclab for identifying and reporting this issue. (en)

Legacy QID Mappings

  • 150367 Apache Tomcat HTTP Request Smuggling Vulnerability (CVE-2021-33037)
  • 178743 Debian Security Update for tomcat8 (DLA 2733-1)
  • 178746 Debian Security Update for tomcat9 (DSA 4952-1)
  • 180184 Debian Security Update for tomcat9 (CVE-2021-33037)
  • 198724 Ubuntu Security Notification for Tomcat Vulnerabilities (USN-5360-1)
  • 239916 Red Hat Update for red hat jboss web server 5.6.0 (RHSA-2021:4861)
  • 296065 Oracle Solaris 11.4 Support Repository Update (SRU) 39.107.1 Missing (CPUOCT2021)
  • 352800 Amazon Linux Security Advisory for tomcat8: ALAS-2021-1535
  • 356206 Amazon Linux Security Advisory for tomcat : ALASTOMCAT9-2023-007
  • 356267 Amazon Linux Security Advisory for tomcat : ALASTOMCAT8.5-2023-007
  • 376076 F5 BIG-IP Application Security Manager (ASM), Local Traffic Manager (LTM), Access Policy Manager (APM) Apache Tomcat Vulnerability (K32469285)
  • 690073 Free Berkeley Software Distribution (FreeBSD) Security Update for tomcat (d34bef0b-f312-11eb-b12b-fc4dd43e2b6a)
  • 710609 Gentoo Linux Apache Tomcat Multiple Vulnerabilities (GLSA 202208-34)
  • 730141 Apache Tomcat HTTP Request Smuggling Vulnerability (CVE-2021-33037)
  • 730327 Atlassian Jira Server Multiple Security Vulnerabilities (JRASERVER-73171, JRASERVER-73071, JRASERVER-73070)
  • 751320 SUSE Enterprise Linux Security Update for tomcat (SUSE-SU-2021:3602-1)
  • 751355 OpenSUSE Security Update for tomcat (openSUSE-SU-2021:3672-1)
  • 751364 SUSE Enterprise Linux Security Update for tomcat (SUSE-SU-2021:3669-1)
  • 751365 SUSE Enterprise Linux Security Update for tomcat (SUSE-SU-2021:3670-1)
  • 751370 OpenSUSE Security Update for tomcat (openSUSE-SU-2021:1490-1)
  • 980269 Java (maven) Security Update for org.apache.tomcat:tomcat (GHSA-4vww-mc66-62m6)

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