KM03633906 - Backup Navigator. Apache Tomcat vulnerability, CVE 2020-1938

  • KM03633906
  • 14-Apr-2020
  • 14-Apr-2020

Summary

A vulnerability in Apache Tomcat was addressed by Micro Focus Backup Navigator. The vulnerability could be exploited to file content disclosure of the web application or remote code execution. 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 defense-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. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-1938

Reference

 

SUPPORT COMMUNICATION - SECURITY BULLETIN

Potential Security Impact: File content disclosure / remote code execution in Apache Tomcat

 

VULNERABILITY SUMMARY

 

A vulnerability in Apache Tomcat was addressed by Micro Focus Backup Navigator. The vulnerability could be exploited to file content disclosure of the web application or remote code execution.

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 defense-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.

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-1938

CVE References:

CVE-2020-1938

SUPPORTED SOFTWARE VERSIONS*: ONLY impacted versions are listed.

Micro Focus Backup Navigator 8.x

Micro Focus Backup Navigator 9.x

Micro Focus Backup Navigator 10.0 to 10.60

 

CVSS Version 3.0 and Version 2.0 Base Metrics

Reference

V3 Vector

V3 Base Score

V2 Vector

V2 Base Score

CVE-2020-1938

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

9.8

 (AV:N/AC:L/Au:N/C:P/I:P/A:P)

7.5

RESOLUTION:

Micro Focus has made the following mitigation information available to resolve the vulnerability for the impacted versions of Backup Navigator:

Windows Environment

1.       Stop Tomcat web server service

Services -> Apache Tomcat service -> Stop

2.       Open Tomcat server.xml configuration file in Backup Navigator installation folder

<Backup_Navigator_installation_path>/webserver/conf/server.xml

3.       Disable AJP connector by commenting out following line in server.xml file:

<Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />

.. wrap with comment code below

<!-- <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />  -->

.. and save

4.       Start Tomcat web server service

Services -> Apache Tomcat service -> Start

 

Linux Environment

1.       Stop Tomcat web server service

# service tomcat stop

2.       Open server.xml configuration file in Tomcat directory

# sudo nano /opt/apache-tomcat/conf/server.xml

3.       Disable AJP connector by commenting out following line in server.xml file:

<Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />

.. wrap with comment code below

<!-- <Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />  -->

.. and save

4.       Start Tomcat web server service

# service tomcat start

 

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