CWE-105: Struts: Form Field Without Validator

Extended Description

Omitting validation for even a single input field may give attackers the leeway they need to compromise the product. Although J2EE applications are not generally susceptible to memory corruption attacks, if a J2EE application interfaces with native code that does not perform array bounds checking, an attacker may be able to use an input validation mistake in the J2EE application to launch a buffer overflow attack.

Code Examples & CVEs

Demonstrative Examples

In the following example the Java 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.

The validator XML file, validator.xml, provides the validation for the form fields of the RegistrationForm.

BadXML

<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></form></formset></form-validation>

The validator XML file, validator.xml, provides the validation for the form fields of the RegistrationForm.

GoodXML

<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>

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-105 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-105, Struts: Form Field Without Validator, throughout the product lifecycle. Derive review questions, static or dynamic checks, and negative tests from the CWE's causal behavior; define the components and lifecycle stages each check covers; and retain findings with enough evidence to distinguish the root cause from symptoms and impacts. Track escapes and false negatives, then improve the verification plan after every confirmed occurrence.

NIST SP 800-218 Secure Software Development Framework — National Institute of Standards and Technology

Address Struts: Form Field Without Validator during Implementation

MITRE associates mitigation with Implementation; recorded impacts include Unexpected State, and Bypass Protection Mechanism; related weaknesses include CWE-1173, and CWE-20. Use these source-defined anchors to turn CWE-105 into implementation, review, and verification checks for the affected component.

CWE-105: Struts: Form Field Without Validator — MITRE CWE

Triage CWE-105 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-105, Struts: Form Field Without Validator, has evidence of exploitation in the wild. Confirm the CVE-to-CWE root-cause mapping independently before attaching the example, then capture the affected product, required action, and remediation deadline. A missing KEV match is not evidence that the weakness is unexploited, and a KEV entry must not be generalized to every occurrence of this CWE.

Known Exploited Vulnerabilities Catalog — Cybersecurity and Infrastructure Security Agency

Apply precise root-cause mapping to CWE-105

Apply MITRE's full root-cause mapping guidance when using CWE-105, Struts: Form Field Without Validator. Separate weakness language from attacker prerequisites and technical impact, check the entry's abstraction and vulnerability-mapping notes, and prefer the most specific Base or Variant supported by the evidence. Record the rejected alternatives and require an independent review before the mapping is used for remediation trends or program metrics.

CVE to CWE Root Cause Mapping Guidance — MITRE CWE

Validate CWE-105 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-105, Struts: Form Field Without Validator. Confirm the finding describes the causal weakness rather than an impact or attack pattern, compare the abstraction and mapping notes with plausible alternatives, and have a second reviewer challenge the selection. Preserve the evidence and reasoning so recurring defects can be measured against one consistent identifier.

CVE to CWE Root Cause Mapping Quick Tips — MITRE CWE

Frequently Asked Questions

What is CWE-105: Struts: Form Field Without Validator?+

CWE-105: Struts: Form Field Without Validator is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product has a form field that is not validated by a corresponding validation form, which can introduce other weaknesses related to insufficient input validation. Omitting validation for even a single input field may give attackers the leeway they need to compromise the product. Although J2EE applications are not generally susceptible to memory corruption attacks, if a J2EE application interfaces with native code that does not perform array bounds checking, an attacker may be able to use an input validation mistake in the J2EE application to launch a buffer overflow attack.

What are the security consequences of Struts: Form Field Without Validator?+

If exploited, CWE-105 (Struts: Form Field Without Validator) it can compromise Integrity, leading to outcomes such as Unexpected State and Bypass Protection Mechanism.

How do you prevent or mitigate Struts: Form Field Without Validator?+

Recommended mitigations for CWE-105 include: Validate all form fields. If a field is unused, it is still important to constrain it so that it is empty or undefined.

Which programming languages are affected by Struts: Form Field Without Validator?+

CWE-105 commonly affects Java. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

What is the difference between a CWE and a CVE?+

A CWE (Common Weakness Enumeration) like CWE-105 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.

CWE-105: Struts: Form Field Without Validator

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