CWE

Common Weakness Enumeration

A Community-Developed List of Software Weakness Types

CWE/SANS Top 25 Most Dangerous Software Errors
Home > CWE List > CWE- Individual Dictionary Definition (3.1)  
ID

CWE-575: EJB Bad Practices: Use of AWT Swing

Weakness ID: 575
Abstraction: Variant
Structure: Simple
Status: Draft
Presentation Filter:
+ Description
The program violates the Enterprise JavaBeans (EJB) specification by using AWT/Swing.
+ Extended Description
The Enterprise JavaBeans specification requires that every bean provider follow a set of programming guidelines designed to ensure that the bean will be portable and behave consistently in any EJB container. In this case, the program violates the following EJB guideline: "An enterprise bean must not use the AWT functionality to attempt to output information to a display, or to input information from a keyboard." The specification justifies this requirement in the following way: "Most servers do not allow direct interaction between an application program and a keyboard/display attached to the server system."
+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfBaseBase - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.695Use of Low-Level Functionality
+ Relevant to the view "Development Concepts" (CWE-699)
NatureTypeIDName
ChildOfBaseBase - a weakness that is described in an abstract fashion, but with sufficient details to infer specific methods for detection and prevention. More general than a Variant weakness, but more specific than a Class weakness.695Use of Low-Level Functionality
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the software life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and Design
Implementation
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

Java (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Other

Technical Impact: Quality Degradation

+ Demonstrative Examples

Example 1

The following Java example is a simple converter class for converting US dollars to Yen. This converter class demonstrates the improper practice of using a stateless session Enterprise JavaBean that implements an AWT Component and AWT keyboard event listener to retrieve keyboard input from the user for the amount of the US dollars to convert to Yen.

(bad code)
Example Language: Java 
@Stateless
public class ConverterSessionBean extends Component implements KeyListener, ConverterSessionRemote {

/* member variables for receiving keyboard input using AWT API */

...
private StringBuffer enteredText = new StringBuffer();

/* conversion rate on US dollars to Yen */

private BigDecimal yenRate = new BigDecimal("115.3100");

public ConverterSessionBean() {
super();
/* method calls for setting up AWT Component for receiving keyboard input */

...
addKeyListener(this);
}

public BigDecimal dollarToYen(BigDecimal dollars) {
BigDecimal result = dollars.multiply(yenRate);
return result.setScale(2, BigDecimal.ROUND_DOWN);
}

/* member functions for implementing AWT KeyListener interface */

public void keyTyped(KeyEvent event) {
...
}

public void keyPressed(KeyEvent e) {
}

public void keyReleased(KeyEvent e) {
}

/* member functions for receiving keyboard input and displaying output */

public void paint(Graphics g) {...}

...
}

This use of the AWT and Swing APIs within any kind of Enterprise JavaBean not only violates the restriction of the EJB specification against using AWT or Swing within an EJB but also violates the intended use of Enterprise JavaBeans to separate business logic from presentation logic.

The Stateless Session Enterprise JavaBean should contain only business logic. Presentation logic should be provided by some other mechanism such as Servlets or Java Server Pages (JSP) as in the following Java/JSP example.

(good code)
Example Language: Java 
@Stateless
public class ConverterSessionBean implements ConverterSessionRemoteInterface {

/* conversion rate on US dollars to Yen */
private BigDecimal yenRate = new BigDecimal("115.3100");

public ConverterSessionBean() {
}

/* remote method to convert US dollars to Yen */

public BigDecimal dollarToYen(BigDecimal dollars) {
BigDecimal result = dollars.multiply(yenRate);
return result.setScale(2, BigDecimal.ROUND_DOWN);
}
}
(good code)
Example Language: JSP 
<%@ page import="converter.ejb.Converter, java.math.*, javax.naming.*"%>
<%!
private Converter converter = null;
public void jspInit() {
try {
InitialContext ic = new InitialContext();
converter = (Converter) ic.lookup(Converter.class.getName());
} catch (Exception ex) {
System.out.println("Couldn't create converter bean."+ ex.getMessage());
}
}
public void jspDestroy() {
converter = null;
}

%>
<html>
<head><title>Converter</title></head>
<body bgcolor="white">
<h1>Converter</h1>
<hr>
<p>Enter an amount to convert:</p>
<form method="get">
<input type="text" name="amount" size="25"><br>
<p>
<input type="submit" value="Submit">
<input type="reset" value="Reset">
</form>
<%
String amount = request.getParameter("amount");
if ( amount != null && amount.length() > 0 ) {
BigDecimal d = new BigDecimal(amount);
BigDecimal yenAmount = converter.dollarToYen(d);

%>
<p>
<%= amount %> dollars are <%= yenAmount %> Yen.
<p>
<%
}

%>
</body>
</html>
+ Potential Mitigations

Phase: Architecture and Design

Do not use AWT/Swing when writing EJBs.
+ Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
NatureTypeIDName
MemberOfCategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.1001SFP Secondary Cluster: Use of an Improper API
+ Taxonomy Mappings
Mapped Taxonomy NameNode IDFitMapped Node Name
Software Fault PatternsSFP3Use of an improper API
+ Content History
Modifications
Modification DateModifierOrganization
2008-07-01Eric DalciCigital
updated Potential_Mitigations, Time_of_Introduction
2008-09-08CWE Content TeamMITRE
updated Relationships, Other_Notes
2009-10-29CWE Content TeamMITRE
updated Description, Other_Notes
2009-12-28CWE Content TeamMITRE
updated Demonstrative_Examples, Potential_Mitigations
2011-06-01CWE Content TeamMITRE
updated Common_Consequences
2011-06-27CWE Content TeamMITRE
updated Common_Consequences
2012-05-11CWE Content TeamMITRE
updated Relationships
2014-07-30CWE Content TeamMITRE
updated Relationships, Taxonomy_Mappings

More information is available — Please select a different filter.
Page Last Updated: March 29, 2018