An unused validation form indicates that validation logic is not up-to-date.

Resultant

Implementation
It is easy for developers to forget to update validation logic when they remove or rename action form mappings. One indication that validation logic is not being properly maintained is the presence of an unused validation form.

Operation

Other
Quality Degradation

Implementation
Remove the unused Validation Form from the validation.xml file.

In the following example the class RegistrationForm is a Struts framework ActionForm Bean that will maintain user input data from a registration webpage for an online business site. The user will enter registration data and, through the Struts framework, the RegistrationForm bean will maintain the user data in the form fields using the private member variables. The RegistrationForm class uses the Struts validation capability by extending the ValidatorForm class and including the validation for the form fields within the validator XML file, validator.xml.

public class RegistrationForm extends org.apache.struts.validator.ValidatorForm {

// private variables for registration form
private String name;private String address;private String city;private String state;private String zipcode;
// no longer using the phone form field

// private String phone;
private String email;
public RegistrationForm() {super();}

// getter and setter methods for private variables
...
}

<form-validation>
<formset>
<form name="RegistrationForm">
<field property="name" depends="required"><arg position="0" key="prompt.name"/></field><field property="address" depends="required"><arg position="0" key="prompt.address"/></field><field property="city" depends="required"><arg position="0" key="prompt.city"/></field><field property="state" depends="required,mask"><arg position="0" key="prompt.state"/><var><var-name>mask</var-name><var-value>[a-zA-Z]{2}</var-value></var></field><field property="zipcode" depends="required,mask"><arg position="0" key="prompt.zipcode"/><var><var-name>mask</var-name><var-value>\d{5}</var-value></var></field><field property="phone" depends="required,mask"><arg position="0" key="prompt.phone"/><var><var-name>mask</var-name><var-value>^([0-9]{3})(-)([0-9]{4}|[0-9]{4})$</var-value></var></field><field property="email" depends="required,email"><arg position="0" key="prompt.email"/></field>
</form>
</formset>
</form-validation>

However, the validator XML file, validator.xml, for the RegistrationForm class includes the validation form for the user input form field "phone" that is no longer used by the input form and the RegistrationForm class. Any validation forms that are no longer required should be removed from the validator XML file, validator.xml.
The existence of unused forms may be an indication to attackers that this code is out of date or poorly maintained.

Struts: Unused Validation Form

Allowed
This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

7 Pernicious Kingdoms
2006-07-19
Draft 3
2006-07-19

Eric Dalci
Cigital
2008-07-01
updated Potential_Mitigations, Time_of_Introduction

CWE Content Team
MITRE
2008-09-08
updated Description, Relationships, Taxonomy_Mappings, Weakness_Ordinalities

CWE Content Team
MITRE
2010-06-21
updated Demonstrative_Examples

CWE Content Team
MITRE
2011-06-01
updated Common_Consequences

CWE Content Team
MITRE
2011-06-27
updated Common_Consequences

CWE Content Team
MITRE
2012-05-11
updated Relationships

CWE Content Team
MITRE
2012-10-30
updated Potential_Mitigations

CWE Content Team
MITRE
2014-07-30
updated Relationships

CWE Content Team
MITRE
2017-11-08
updated Causal_Nature, Relationships

CWE Content Team
MITRE
2020-02-24
updated References, Relationships

CWE Content Team
MITRE
2022-04-28
updated Relationships

CWE Content Team
MITRE
2023-04-27
updated Relationships

CWE Content Team
MITRE
2023-06-29
updated Mapping_Notes

CWE Content Team
MITRE
2025-12-11
4.19
2025-12-11
updated Description, Modes_of_Introduction