10.12 Do not allow symbolic linking

Information

Symbolic links permit one application to include the libraries from another. This allows for re-use of code but also allows for potential security issues when applications include libraries from other applications to which they should not have access.

Rationale:

Allowing symbolic links makes Tomcat susceptible to directory traversal vulnerability. Also, there is a potential that an application could link to another application to which it should not be linking. On case-insensitive operating systems there is also the threat of source code disclosure.

Solution

In all context.xml, set the allowLinking attribute to false:

<Context
...
<Resources ... allowLinking='false' />
...
</Context>

Default Value:

By default allowLinking has a value of false.

References:

https://tomcat.apache.org/tomcat-9.0-doc/config/resources.html

https://tomcat.apache.org/tomcat-9.0-doc/config/context.html

See Also

https://workbench.cisecurity.org/files/2509

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-6, CSCv7|5.1

Plugin: Unix

Control ID: 9d8bd6364dda7c76fa22c5bd44fe5f39e1e2b4670a46efb86b536a4bf419f550