Answer in brief
CVE-2021-33037 records a Medium severity (CVSS 5.3) vulnerability in Incorrect Transfer-Encoding handling with HTTP/1.0. The current sources do not mark it as known exploited. The current feed maps Apache Software Foundation/Apache Tomcat (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Apache Software Foundation/Apache Tomcat (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:apache:tomee:8.0.6:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:-:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:update_1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:update_10:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:update_2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:update_3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:update_4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:update_5:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:update_6:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:update_7:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:update_8:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:mcafee:epolicy_orchestrator:5.10.0:update_9:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:agile_product_lifecycle_management:9.3.6:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:communications_cloud_native_core_policy:1.14.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:communications_cloud_native_core_service_communication_proxy:1.14.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:communications_diameter_signaling_router:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:communications_instant_messaging_server:10.0.1.5.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:communications_policy_management:12.5.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:communications_pricing_design_center:12.0.0.3.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:communications_session_report_manager:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:communications_session_route_manager:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:graph_server_and_client:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:healthcare_translational_research:4.1.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:hospitality_cruise_shipboard_property_management_system:20.1.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:managed_file_transfer:12.2.1.3.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:managed_file_transfer:12.2.1.4.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:mysql_enterprise_monitor:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:sd-wan_edge:9.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:sd-wan_edge:9.1:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:secure_global_desktop:5.6:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:utilities_testing_accelerator:6.0.0.1.1:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:utilities_testing_accelerator:6.0.0.2.2:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:oracle:utilities_testing_accelerator:6.0.0.3.1:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Apache Software Foundation/Apache Tomcatgeneric | Apache Tomcat 10 10.0.0-M1 to 10.0.6 || Apache Tomcat 9 9.0.0.M1 to 9.0.46 || Apache Tomcat 8 8.5.0 to 8.5.66 | Not reported |
Published upstream
Jul 12, 2021
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 28, 2026
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.
Quoted source text, attributed separately from HOL analysis.