--- id: CVE-2021-33037 title: >- 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 pr… summary: >- 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 pr… severity: medium cvss: 5.3 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N' cwe: - CWE-444 - CWE-444 vendor: apache product: tomcat affected: - 'tomcat >= 8.5.0, <= 8.5.66' - 'tomcat > 9.0.0, <= 9.0.46' - 'tomcat > 10.0.0, <= 10.0.6' - tomee = 8.0.6 - debian_linux = 9.0 - debian_linux = 10.0 - agile_product_lifecycle_management = 9.3.6 - communications_cloud_native_core_policy = 1.14.0 - communications_cloud_native_core_service_communication_proxy = 1.14.0 - 'communications_diameter_signaling_router >= 8.0.0.0, <= 8.5.0.2' - communications_instant_messaging_server = 10.0.1.5.0 - communications_policy_management = 12.5.0 - communications_pricing_design_center = 12.0.0.3.0 - 'communications_session_report_manager >= 8.0.0, <= 8.2.4.0' - 'communications_session_route_manager >= 8.0.0, <= 8.2.4' - graph_server_and_client < 21.4 - healthcare_translational_research = 4.1.0 - hospitality_cruise_shipboard_property_management_system = 20.1.0 - instantis_enterprisetrack = 17.1 - instantis_enterprisetrack = 17.2 - instantis_enterprisetrack = 17.3 - managed_file_transfer = 12.2.1.3.0 - managed_file_transfer = 12.2.1.4.0 - mysql_enterprise_monitor <= 8.0.25 - sd-wan_edge = 9.0 - sd-wan_edge = 9.1 - secure_global_desktop = 5.6 - utilities_testing_accelerator = 6.0.0.1.1 - utilities_testing_accelerator = 6.0.0.2.2 - utilities_testing_accelerator = 6.0.0.3.1 - epolicy_orchestrator < 5.10.0 - epolicy_orchestrator = 5.10.0 patched: - graph_server_and_client 21.4 - epolicy_orchestrator 5.10.0 published: '2021-07-12' updated: '2026-08-25' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-33037' references: - url: 'https://kc.mcafee.com/corporate/index?page=content&id=SB10366' label: security@apache.org - url: >- https://lists.apache.org/thread.html/r290aee55b72811fd19e75ac80f6143716c079170c5671b96932ed44b%40%3Ccommits.tomee.apache.org%3E label: security@apache.org - url: >- https://lists.apache.org/thread.html/r40f921575aee8d7d34e53182f862c45cbb8f3d898c9d4e865c2ec262%40%3Ccommits.tomee.apache.org%3E label: security@apache.org - url: >- https://lists.apache.org/thread.html/r612a79269b0d5e5780c62dfd34286a8037232fec0bc6f1a7e60c9381%40%3Cannounce.tomcat.apache.org%3E label: security@apache.org - url: >- https://lists.apache.org/thread.html/rc6ef52453bb996a98cb45442871a1db56b7c349939e45d829bf9ae37%40%3Ccommits.tomee.apache.org%3E label: security@apache.org - url: >- https://lists.apache.org/thread.html/rd0dfea39829bc0606c936a16f6fca338127c86c0a1083970b45ac8d2%40%3Ccommits.tomee.apache.org%3E label: security@apache.org - url: >- https://lists.apache.org/thread.html/re01e7e93154e8bdf78a11a23f9686427bd3d51fc6e12c508645567b7%40%3Ccommits.tomee.apache.org%3E label: security@apache.org - url: >- https://lists.apache.org/thread.html/rf1b54fd3f52f998ca4829159a88cc4c23d6cef5c6447d00948e75c97%40%3Ccommits.tomee.apache.org%3E label: security@apache.org - url: 'https://lists.debian.org/debian-lts-announce/2021/08/msg00009.html' label: security@apache.org - url: 'https://security.gentoo.org/glsa/202208-34' label: security@apache.org - url: 'https://security.netapp.com/advisory/ntap-20210827-0007/' label: security@apache.org - url: 'https://www.debian.org/security/2021/dsa-4952' label: security@apache.org - url: 'https://www.oracle.com//security-alerts/cpujul2021.html' label: security@apache.org - url: 'https://www.oracle.com/security-alerts/cpuapr2022.html' label: security@apache.org - url: 'https://www.oracle.com/security-alerts/cpujan2022.html' label: security@apache.org - url: 'https://www.oracle.com/security-alerts/cpuoct2021.html' label: security@apache.org - url: 'https://kc.mcafee.com/corporate/index?page=content&id=SB10366' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/r290aee55b72811fd19e75ac80f6143716c079170c5671b96932ed44b%40%3Ccommits.tomee.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/r40f921575aee8d7d34e53182f862c45cbb8f3d898c9d4e865c2ec262%40%3Ccommits.tomee.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/r612a79269b0d5e5780c62dfd34286a8037232fec0bc6f1a7e60c9381%40%3Cannounce.tomcat.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/rc6ef52453bb996a98cb45442871a1db56b7c349939e45d829bf9ae37%40%3Ccommits.tomee.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/rd0dfea39829bc0606c936a16f6fca338127c86c0a1083970b45ac8d2%40%3Ccommits.tomee.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/re01e7e93154e8bdf78a11a23f9686427bd3d51fc6e12c508645567b7%40%3Ccommits.tomee.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/rf1b54fd3f52f998ca4829159a88cc4c23d6cef5c6447d00948e75c97%40%3Ccommits.tomee.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2021/08/msg00009.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://security.gentoo.org/glsa/202208-34' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://security.netapp.com/advisory/ntap-20210827-0007/' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.debian.org/security/2021/dsa-4952' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com//security-alerts/cpujul2021.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com/security-alerts/cpuapr2022.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com/security-alerts/cpujan2022.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com/security-alerts/cpuoct2021.html' label: af854a3a-2127-422b-91ae-364da2661108 tags: - nvd epss: 0.75353 epssPercentile: 0.99503 ingestedAt: '2026-08-25T17:29:31.279Z' --- ## Overview 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 - `tomcat >= 8.5.0, <= 8.5.66` - `tomcat > 9.0.0, <= 9.0.46` - `tomcat > 10.0.0, <= 10.0.6` - `tomee = 8.0.6` - `debian_linux = 9.0` - `debian_linux = 10.0` - `agile_product_lifecycle_management = 9.3.6` - `communications_cloud_native_core_policy = 1.14.0` - `communications_cloud_native_core_service_communication_proxy = 1.14.0` - `communications_diameter_signaling_router >= 8.0.0.0, <= 8.5.0.2` - `communications_instant_messaging_server = 10.0.1.5.0` - `communications_policy_management = 12.5.0` - `communications_pricing_design_center = 12.0.0.3.0` - `communications_session_report_manager >= 8.0.0, <= 8.2.4.0` - `communications_session_route_manager >= 8.0.0, <= 8.2.4` - `graph_server_and_client < 21.4` - `healthcare_translational_research = 4.1.0` - `hospitality_cruise_shipboard_property_management_system = 20.1.0` - `instantis_enterprisetrack = 17.1` - `instantis_enterprisetrack = 17.2` - `instantis_enterprisetrack = 17.3` - `managed_file_transfer = 12.2.1.3.0` - `managed_file_transfer = 12.2.1.4.0` - `mysql_enterprise_monitor <= 8.0.25` - `sd-wan_edge = 9.0` - `sd-wan_edge = 9.1` - `secure_global_desktop = 5.6` - `utilities_testing_accelerator = 6.0.0.1.1` - `utilities_testing_accelerator = 6.0.0.2.2` - `utilities_testing_accelerator = 6.0.0.3.1` - `epolicy_orchestrator < 5.10.0` - `epolicy_orchestrator = 5.10.0` ## Remediation Upgrade past the affected range: - `graph_server_and_client 21.4` - `epolicy_orchestrator 5.10.0`