CVE-2020-1938: Apache Tomcat Improper Privilege Management Vulnerability
Critical severity, CVSS 9.8. Actively exploited: in CISA KEV since 2022-03-03. EPSS: 99.3% chance of exploitation in the next 30 days.
When using the Apache JServ Protocol (AJP), care must be taken when trusting incoming connections to Apache Tomcat. Tomcat treats AJP connections as having higher trust than, for example, a similar HTTP connection. If such connections are available to an attacker, they can be exploited in ways that may be surprising. In Apache Tomcat 9.0.0.M1 to 9.0.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99, Tomcat shipped with an AJP Connector enabled by default that listened on all configured IP addresses. It was expected (and recommended in the security guide) that this Connector would be disabled if not required. This vulnerability report identified a mechanism that allowed: - returning arbitrary files from anywhere in the web application - processing any file in the web application as a JSP Further, if the web application allowed file upload and stored those files within the web application (or the attacker was able to control the content of the web application by some other means) then this, along with the ability to process a file as a JSP, made remote code execution possible. It is important to note that mitigation is only required if an AJP port is accessible to untrusted users. Users wishing to take a defence-in-depth approach and block the vector that permits returning arbitrary files and execution as JSP may upgrade to Apache Tomcat 9.0.31, 8.5.51 or 7.0.100 or later. A number of changes were made to the default AJP Connector configuration in 9.0.31 to harden the default configuration. It is likely that users upgrading to 9.0.31, 8.5.51 or 7.0.100 or later will need to make small changes to their configurations.
Affected products
- Apache Geode: version 1.12.0 only
- Apache Tomcat: from 7.0.0, before 7.0.100 (fixed in 7.0.100); from 8.5.0, before 8.5.51 (fixed in 8.5.51); from 9.0.0, before 9.0.31 (fixed in 9.0.31)
- Blackberry Good Control: up to and including 5.2.58.38
- Blackberry Workspaces Server: version 7.0.1 only; version 7.1.2 only; version 8.1.0 only; version 9.0 only
- Debian Debian Linux: version 8.0 only; version 9.0 only; version 10.0 only
- Fedoraproject Fedora: version 30 only; version 31 only; version 32 only
- Netapp Data Availability Services: affected versions not specified
- Netapp Oncommand System Manager: from 3.0.0, up to and including 3.1.3
- Opensuse Leap: version 15.1 only
- Oracle Agile Engineering Data Management: version 6.2.1.0 only
- Oracle Agile Product Lifecycle Management: version 9.3.3 only; version 9.3.5 only; version 9.3.6 only
- Oracle Communications Element Manager: version 8.1.1 only; version 8.2.0 only; version 8.2.1 only
- Oracle Communications Instant Messaging Server: version 10.0.1.4.0 only
- Oracle Health Sciences Empirica Inspections: version 1.0.1.2 only
- Oracle Health Sciences Empirica Signal: version 7.3.3 only
- Oracle Hospitality Guest Access: version 4.2.0 only; version 4.2.1 only
- Oracle Instantis Enterprisetrack: from 17.1, up to and including 17.3
- Oracle MySQL Enterprise Monitor: up to and including 4.0.12; from 8.0.0, up to and including 8.0.20
- Oracle Siebel UI Framework: up to and including 20.5
- Oracle Transportation Management: version 6.3.7 only
- Oracle Workload Manager: version 12.2.0.1 only; version 18c only; version 19c only
Published 2020-02-24. Last modified 2026-08-25.