CWE-574: EJB Bad Practices: Use of Synchronization Primitives

Description

The product violates the Enterprise JavaBeans (EJB) specification by using thread synchronization primitives.

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: "An enterprise bean must not use thread synchronization primitives to synchronize execution of multiple instances." The specification justifies this requirement in the following way: "This rule is required to ensure consistent runtime semantics because while some EJB containers may use a single JVM to execute all enterprise bean's instances, others may distribute the instances across multiple JVMs."

Potential Impact

Other

Quality Degradation

Demonstrative Examples

In the following Java example a Customer Entity EJB provides access to customer information in a database for a business application.

Bad

@Entitypublic class Customer implements Serializable {
                     
                        private String id;private String firstName;private String lastName;private Address address;
                           public Customer() {...}
                           public Customer(String id, String firstName, String lastName) {...}
                           @Idpublic String getCustomerId() {...}
                           public synchronized void setCustomerId(String id) {...}
                           public String getFirstName() {...}
                           public synchronized void setFirstName(String firstName) {...}
                           public String getLastName() {...}
                           public synchronized void setLastName(String lastName) {...}
                           @OneToOne()public Address getAddress() {...}
                           public synchronized void setAddress(Address address) {...}
                     }

However, the customer entity EJB uses the synchronized keyword for the set methods to attempt to provide thread safe synchronization for the member variables. The use of synchronized methods violate the restriction of the EJB specification against the use synchronization primitives within EJBs. Using synchronization primitives may cause inconsistent behavior of the EJB when used within different EJB containers.

Mitigations & Prevention

Implementation

Do not use Synchronization Primitives when writing EJBs.

Taxonomy Mappings

Software Fault Patterns: SFP3 — Use of an improper API

Frequently Asked Questions

What is CWE-574?

CWE-574 (EJB Bad Practices: Use of Synchronization Primitives) is a software weakness identified by MITRE's Common Weakness Enumeration. It is classified as a Variant-level weakness. The product violates the Enterprise JavaBeans (EJB) specification by using thread synchronization primitives.

How can CWE-574 be exploited?

Attackers can exploit CWE-574 (EJB Bad Practices: Use of Synchronization Primitives) to quality degradation. This weakness is typically introduced during the Implementation phase of software development.

How do I prevent CWE-574?

Key mitigations include: Do not use Synchronization Primitives when writing EJBs.

What is the severity of CWE-574?

CWE-574 is classified as a Variant-level weakness (Low-Medium abstraction). Its actual severity depends on the specific context and how the weakness manifests in your application.