The product violates the Enterprise JavaBeans (EJB) specification by using the class loader.
View on MITREThe 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 product violates the following EJB guideline: "The enterprise bean must not attempt to create a class loader; obtain the current class loader; set the context class loader; set security manager; create a new security manager; stop the JVM; or change the input, output, and error streams." The specification justifies this requirement in the following way: "These functions are reserved for the EJB container. Allowing the enterprise bean to use these functions could compromise security and decrease the container's ability to properly manage the runtime environment."
Do not use the Class Loader when writing EJBs.
No detection method information available for this CWE.
The following Java example is a simple stateless Enterprise JavaBean that retrieves the interest rate for the number of points for a mortgage. The interest rates for various points are retrieved from an XML document on the local file system, and the EJB uses the Class Loader for the EJB class to obtain the XML document from the local file system as an input stream.
This use of the Java Class Loader class within any kind of Enterprise JavaBean violates the restriction of the EJB specification against obtaining the current class loader as this could compromise the security of the application using the EJB.
@Statelesspublic class InterestRateBean implements InterestRateRemote { private Document interestRateXMLDocument = null; public InterestRateBean() { try { // get XML document from the local filesystem as an input stream // using the ClassLoader for this class ClassLoader loader = this.getClass().getClassLoader();InputStream in = loader.getResourceAsStream(Constants.INTEREST_RATE_FILE); DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();DocumentBuilder db = dbf.newDocumentBuilder();interestRateXMLDocument = db.parse(interestRateFile);} catch (IOException ex) {...} } public BigDecimal getInterestRate(Integer points) {return getInterestRateFromXML(points);} /* member function to retrieve interest rate from XML document on the local file system */ private BigDecimal getInterestRateFromXML(Integer points) {...} }An EJB is also restricted from creating a custom class loader and creating a class and instance of a class from the class loader, as shown in the following example.
@Statelesspublic class LoaderSessionBean implements LoaderSessionRemote { public LoaderSessionBean() {try {ClassLoader loader = new CustomClassLoader();Class c = loader.loadClass("someClass");Object obj = c.newInstance();/* perform some task that uses the new class instance member variables or functions */...} catch (Exception ex) {...}} public class CustomClassLoader extends ClassLoader { } }CWE-578: EJB Bad Practices: Use of Class Loader is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product violates the Enterprise JavaBeans (EJB) specification by using the class loader. 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 product violates the following EJB guideline: "The enterprise bean must not attempt to create a class loader; obtain the current class loader; set the context class loader; set security manager; create a new security manager; stop the JVM; or change the input, output, and error streams." The specification justifies this requirement in the following way: "These functions are reserved for the EJB container. Allowing the enterprise bean to use these functions could compromise security and decrease the container's ability to properly manage the runtime environment."
If exploited, CWE-578 (EJB Bad Practices: Use of Class Loader) it can compromise Confidentiality, Integrity, Availability and Other, leading to outcomes such as Execute Unauthorized Code or Commands and Varies by Context.
Recommended mitigations for CWE-578 include: Do not use the Class Loader when writing EJBs.
CWE-578 commonly affects Java. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.
A CWE (Common Weakness Enumeration) like CWE-578 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.