cis-tomcat101-10-12

name	cis-tomcat101-10.12
description	Do not allow symbolic linking (Automated)
category	cis-tomcat
version	1.0.0
author	cyberstrike-official
tags	["cis","tomcat","linux","java","configuration","hardening","security"]
cis_id	10.12
cis_benchmark	CIS Apache Tomcat 10.1 Benchmark v1.0.0
tech_stack	["linux","tomcat","java"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

10.12 Do not allow symbolic linking (Automated)

Description

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.

Audit Procedure

Ensure the allowLinking attribute in all context.xml does not exist or is set to false.

# find . -name context.xml | xargs grep "allowLinking"

Remediation

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

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

CIS Controls

Controls Version	Control	IG 1	IG 2	IG 3
v8	2.7 Allowlist Authorized Scripts Use technical controls, such as digital signatures and version control, to ensure that only authorized scripts, such as specific .ps1, .py, etc., files, are allowed to execute. Block unauthorized scripts from executing. Reassess bi-annually, or more frequently.			●
v7	5.1 Establish Secure Configurations Maintain documented, standard security configuration standards for all authorized operating systems and software.