CWE-594: J2EE Framework: Saving Unserializable Objects to Disk

Extended Description

In heavy load conditions, most J2EE application frameworks flush objects to disk to manage memory requirements of incoming requests. For example, session scoped objects, and even application scoped objects, are written to disk when required. While these application frameworks do the real work of writing objects to disk, they do not enforce that those objects be serializable, thus leaving the web application vulnerable to crashes induced by serialization failure. An attacker may be able to mount a denial of service attack by sending enough requests to the server to force the web application to save objects to disk.

Code Examples & CVEs

Demonstrative Examples

In the following Java example, a Customer Entity JavaBean provides access to customer information in a database for a business application. The Customer Entity JavaBean is used as a session scoped object to return customer information to a Session EJB.

However, the Customer Entity JavaBean is an unserialized object which can cause serialization failure and crash the application when the J2EE container attempts to write the object to the system. Session scoped objects must implement the Serializable interface to ensure that the objects serialize properly.

BadJava

@Entitypublic class Customer {                                               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 void setCustomerId(String id) {...}                            public String getFirstName() {...}                            public void setFirstName(String firstName) {...}                            public String getLastName() {...}                            public void setLastName(String lastName) {...}                            @OneToOne()public Address getAddress() {...}                            public void setAddress(Address address) {...}                                                                  }

GoodJava

public class Customer implements Serializable {...}

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-594 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-594, J2EE Framework: Saving Unserializable Objects to Disk, 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 J2EE Framework: Saving Unserializable Objects to Disk during Architecture and Design

MITRE associates mitigation with Architecture and Design, and Implementation; recorded impacts include Modify Application Data, and DoS: Crash, Exit, or Restart; related weaknesses include CWE-1076. Use these source-defined anchors to turn CWE-594 into implementation, review, and verification checks for the affected component.

CWE-594: J2EE Framework: Saving Unserializable Objects to Disk — MITRE CWE

Triage CWE-594 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-594, J2EE Framework: Saving Unserializable Objects to Disk, 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-594

Apply MITRE's full root-cause mapping guidance when using CWE-594, J2EE Framework: Saving Unserializable Objects to Disk. 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-594 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-594, J2EE Framework: Saving Unserializable Objects to Disk. 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-594: J2EE Framework: Saving Unserializable Objects to Disk?+

CWE-594: J2EE Framework: Saving Unserializable Objects to Disk is a Common Weakness Enumeration (CWE) entry maintained by MITRE. When the J2EE container attempts to write unserializable objects to disk there is no guarantee that the process will complete successfully. In heavy load conditions, most J2EE application frameworks flush objects to disk to manage memory requirements of incoming requests. For example, session scoped objects, and even application scoped objects, are written to disk when required. While these application frameworks do the real work of writing objects to disk, they do not enforce that those objects be serializable, thus leaving the web application vulnerable to crashes induced by serialization failure. An attacker may be able to mount a denial of service attack by sending enough requests to the server to force the web application to save objects to disk.

What are the security consequences of J2EE Framework: Saving Unserializable Objects to Disk?+

If exploited, CWE-594 (J2EE Framework: Saving Unserializable Objects to Disk) it can compromise Integrity and Availability, leading to outcomes such as Modify Application Data and DoS: Crash, Exit, or Restart.

How do you prevent or mitigate J2EE Framework: Saving Unserializable Objects to Disk?+

Recommended mitigations for CWE-594 include: All objects that become part of session and application scope must implement the java.io.Serializable interface to ensure serializability of containing objects.

Which programming languages are affected by J2EE Framework: Saving Unserializable Objects to Disk?+

CWE-594 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-594 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-594: J2EE Framework: Saving Unserializable Objects to Disk

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