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CVE DATABASE  /  CVE-2020-1938

CVE-2020-1938

Apache Tomcat Improper Privilege Management Vulnerability

CVSS 9.8 · CRITICAL ⚠ CISA KEV — ACTIVELY EXPLOITED
On the CISA KEV catalog

Confirmed exploited in the wild. Added 2022-03-03. Federal remediation due 2022-03-17.
Required action: Apply updates per vendor instructions.

Summary

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.

CVSS 3.1 breakdown

Base score9.8 (CRITICAL)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vectorNETWORK
Attack complexityLOW
Privileges requiredNONE
User interactionNONE
ScopeUNCHANGED
ConfidentialityHIGH
IntegrityHIGH
AvailabilityHIGH

Affected products

Apache geodeApache tomcatFedoraproject fedoraOracle agile engineering data managementOracle agile plmOracle communications element managerOracle communications instant messaging serverOracle health sciences empirica inspectionsOracle health sciences empirica signalOracle hospitality guest accessOracle instantis enterprisetrackOracle mysql enterprise monitorOracle siebel ui frameworkOracle transportation managementOracle workload managerDebian debian linuxOpensuse leapBlackberry good controlBlackberry workspaces serverNetapp data availability services
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References

Data: NIST NVD + CISA KEV. NVD last modified 2025-10-27. Always verify against the vendor advisory before acting.

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