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CVE-2020-1938: Apache Tomcat Improper Privilege Management Vulnerability

CVE-2020-1938 is rated critical with a CVSS v3.1 base score of 9.8 and affects Apache Tomcat, along with 20 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2022-03-03, which means exploitation in the wild has been observed.

Vulnerability description

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.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Affected products

  • Apache Tomcat: from 7.0.0 before 7.0.100; from 8.5.0 before 8.5.51; from 9.0.0 before 9.0.31
  • Apache Geode: 1.12.0
  • Fedoraproject: 30; 31; 32
  • Oracle Agile Engineering Data Management: 6.2.1.0
  • Oracle Agile Product Lifecycle Management: 9.3.3; 9.3.5; 9.3.6
  • Oracle Communications Element Manager: 8.1.1; 8.2.0; 8.2.1
  • Oracle Communications Instant Messaging Server: 10.0.1.4.0
  • Oracle Health Sciences Empirica Inspections: 1.0.1.2
  • Oracle Health Sciences Empirica Signal: 7.3.3
  • Oracle Hospitality Guest Access: 4.2.0; 4.2.1
  • 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: 6.3.7
  • Oracle Workload Manager: 12.2.0.1; 18c; 19c

References