CWE-579 Variant Draft

J2EE Bad Practices: Non-serializable Object Stored in Session

This vulnerability occurs when a Java application stores an object in the user's session that cannot be serialized, which can break critical application features and hurt reliability.

Definition

What is CWE-579?

This vulnerability occurs when a Java application stores an object in the user's session that cannot be serialized, which can break critical application features and hurt reliability.
Modern Java applications often run across multiple servers (JVMs) for better performance and uptime. To present a seamless experience, the application server needs to copy a user's session data between these servers, especially if one fails. This replication process requires every object stored in the `HttpSession` to be serializable—that is, convertible into a byte stream for transfer. If a non-serializable object is placed in the session, this failover mechanism breaks, potentially causing errors during server scaling or outages. For developers, this means any class whose instance is added to the session via `setAttribute()` must implement the `java.io.Serializable` interface. Common culprits include custom helper classes, third-party library objects, or database connections that weren't designed for serialization. Failing to ensure this prevents session replication, undermining the reliability benefits of a clustered deployment and leading to inconsistent user experiences during infrastructure changes.
Real-world impact

Real-world CVEs caused by CWE-579

No public CVE references are linked to this CWE in MITRE's catalog yet.

How attackers exploit it

Step-by-step attacker path

  1. 1

    Identify a code path that handles untrusted input without validation.

  2. 2

    Craft a payload that exercises the unsafe behavior — injection, traversal, overflow, or logic abuse.

  3. 3

    Deliver the payload through a normal request and observe the application's reaction.

  4. 4

    Iterate until the response leaks data, executes attacker code, or escalates privileges.

Vulnerable code example

Vulnerable Java

The following class adds itself to the session, but because it is not serializable, the session can no longer be replicated.

Vulnerable Java 
public class DataGlob {
  		String globName;
  		String globValue;
  		public void addToSession(HttpSession session) {
  			session.setAttribute("glob", this);
  		}
  }
Secure code example

Secure pseudo

Secure pseudo 
// Validate, sanitize, or use a safe API before reaching the sink.
function handleRequest(input) {
  const safe = validateAndEscape(input);
  return executeWithGuards(safe);
}
What changed: the unsafe sink is replaced (or the input is validated/escaped) so the same payload no longer triggers the weakness.
Prevention checklist

How to prevent CWE-579

  • Implementation In order for session replication to work, the values the product stores as attributes in the session must implement the Serializable interface.
Detection signals

How to detect CWE-579

Automated Static Analysis High

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Plexicus auto-fix

Plexicus auto-detects CWE-579 and opens a fix PR in under 60 seconds.

Codex Remedium scans every commit, identifies this exact weakness, and ships a reviewer-ready pull request with the patch. No tickets. No hand-offs.

Get a demo Try Plexicus free
Frequently asked questions

Frequently asked questions

What is CWE-579?

This vulnerability occurs when a Java application stores an object in the user's session that cannot be serialized, which can break critical application features and hurt reliability.

How serious is CWE-579?

MITRE has not published a likelihood-of-exploit rating for this weakness. Treat it as medium-impact until your threat model proves otherwise.

What languages or platforms are affected by CWE-579?

MITRE lists the following affected platforms: Java.

How can I prevent CWE-579?

In order for session replication to work, the values the product stores as attributes in the session must implement the Serializable interface.

How does Plexicus detect and fix CWE-579?

Plexicus's SAST engine matches the data-flow signature for CWE-579 on every commit. When a match is found, our Codex Remedium agent opens a fix PR with the corrected code, tests, and a one-line summary for the reviewer.

Where can I learn more about CWE-579?

MITRE publishes the canonical definition at https://cwe.mitre.org/data/definitions/579.html. You can also reference OWASP and NIST documentation for adjacent guidance.

Related weaknesses

Weaknesses related to CWE-579

CWE-573 Parent

Improper Following of Specification by Caller

This weakness occurs when software fails to properly follow the documented rules, protocols, or requirements of an external component it…

CWE-103 Sibling

Struts: Incomplete validate() Method Definition

This vulnerability occurs in a Struts application when a validator form either completely omits a validate() method or includes one but…

CWE-104 Sibling

Struts: Form Bean Does Not Extend Validation Class

This vulnerability occurs in Apache Struts applications when a form bean class does not properly extend the framework's validation class.…

CWE-243 Sibling

Creation of chroot Jail Without Changing Working Directory

This vulnerability occurs when a program creates a chroot jail but fails to change its current working directory afterward. Because the…

CWE-253 Sibling

Incorrect Check of Function Return Value

This vulnerability occurs when a program misinterprets or improperly validates the return value from a function, causing it to miss…

CWE-296 Sibling

Improper Following of a Certificate's Chain of Trust

This vulnerability occurs when software fails to properly validate the entire certificate chain back to a trusted root authority. This…

CWE-304 Sibling

Missing Critical Step in Authentication

This vulnerability occurs when a software authentication process omits a required step, weakening its overall security.

CWE-325 Sibling

Missing Cryptographic Step

This vulnerability occurs when a software implementation skips a critical step in a cryptographic process, resulting in security that is…

CWE-329 Sibling

Generation of Predictable IV with CBC Mode

This vulnerability occurs when software uses a predictable or reused Initialization Vector (IV) with Cipher Block Chaining (CBC) mode…

Resources

Further reading

Ready when you are

Don't Let Security
Weigh You Down.

Stop choosing between AI velocity and security debt. Plexicus is the only platform that runs Vibe Coding Security and ASPM in parallel — one workflow, every codebase.