cyberstrikeus 10.18 Use the logEffectiveWebXml and metadata-complete settings for deploying applications in production (Automated)
Description
Both fragments and annotations give rise to security concerns. web.xml contains a metadata-complete attribute on the web-app element whose binary value defines whether other sources of metadata should be considered when deploying this web application, this includes annotations on class files (@WebServlet, but also @WebListener, @WebFilter, ...), web-fragment.xml as well as classes located in WEB-INF/classes. In addition, you can also allow you to log the effective web.xml, when an application starts, and the effective web.xml is the result of taking the main web.xml for your application merging in all the fragments applying all the annotations. By logging that, you are able to review it, and see if that is in fact what you actually want.
Rationale
Enable logEffectiveWebXml will allow you to log the effective web.xml and you are able to see if that is in fact what you actually want. Enable metadata-complete so that the web.xml is the only metadata considered.
Audit Procedure
- Review each application's
web.xmlfile located in the applications$CATALINA_HOME/webapps/<app_name>/WEB-INF/web.xmland determine if the logEffectiveWebXml is properly is set.
<web-app
...
metadata-complete="true"
...
>
- Review each application's
context.xmlfile located in the applications$CATALINA_HOME/webapps/<app_name>/META-INF/context.xmland determine if the metadata-complete property is set.
<Context
...
logEffectiveWebXml="true"
...
>
Remediation
- Set the
metadata-completevalue in theweb.xmlin each of the applications totrue.
Note: The metadata-complete option is not enough to disable all of annotation scanning. If there is a ServletContainerInitializer with a @HandlesTypes annotation, Tomcat has to scan your application for classes that use annotations or interfaces specified in that annotation.
- Set the
logEffectiveWebXmlvalue in thecontext.xmlin each of the application totrue.
Default Value
If logEffectiveWebXml and/or metadata-complete is/are not specified, the default value is false.
References
- https://tomcat.apache.org/tomcat-9.0-doc/config/context.html
- https://alexismp.wordpress.com/2010/07/28/servlet-3-0-fragments-and-web-xml-to-rule-them-all/
CIS Controls
| Controls Version | Control | IG 1 | IG 2 | IG 3 |
|---|---|---|---|---|
| v8 | 8.5 Collect Detailed Audit LogsConfigure detailed audit logging for enterprise assets containing sensitive data. Include event source, date, username, timestamp, source addresses, destination addresses, and other useful elements that could assist in a forensic investigation. | ● | ● | |
| v7 | 6.3 Enable Detailed LoggingEnable system logging to include detailed information such as an event source, date, user, timestamp, source addresses, destination addresses, and other useful elements. | ● | ● |
Profile
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