CWE-499 Variant Draft High likelihood

Serializable Class Containing Sensitive Data

This vulnerability occurs when a class containing sensitive information, such as credentials or personal data, is left serializable by default. Because the class does not explicitly prevent…

Definition

What is CWE-499?

This vulnerability occurs when a class containing sensitive information, such as credentials or personal data, is left serializable by default. Because the class does not explicitly prevent serialization, its internal data can be accessed and extracted by other parts of the application or external processes.
When a class implements Serializable without safeguards, it effectively becomes an open book. The sensitive fields within it cannot be truly hidden; any other class with serialization access can reconstruct the object and read its private data, bypassing intended access controls. This exposes critical information that should remain protected. To prevent this, developers should explicitly deny serialization for sensitive classes by marking them as 'transient' or overriding serialization methods. While SAST tools can detect this pattern, Plexicus uses AI to not only identify the flaw but also generate the specific code fix—such as adding a custom `readObject` method—saving significant manual remediation time across your codebase.
Auswirkungen in der Praxis

Real-world CVEs caused by CWE-499

Bisher sind in MITREs Katalog keine öffentlichen CVE-Referenzen mit dieser CWE verknüpft.

Wie Angreifer es ausnutzen

Angreiferpfad Schritt für Schritt

  1. 1

    Identifiziere einen Codepfad, der nicht vertrauenswürdige Eingaben ohne Validierung verarbeitet.

  2. 2

    Erzeuge eine Payload, die das unsichere Verhalten auslöst — Injection, Traversal, Overflow oder Logik-Missbrauch.

  3. 3

    Liefere die Payload über einen normalen Request aus und beobachte die Reaktion der Anwendung.

  4. 4

    Iteriere, bis die Antwort Daten preisgibt, Angreifer-Code ausführt oder Berechtigungen eskaliert.

Verwundbares Codebeispiel

Vulnerable Java

This code creates a new record for a medical patient:

Verwundbar Java
class PatientRecord {
  	private String name;
  	private String socialSecurityNum;
  	public Patient(String name,String ssn) {
  		this.SetName(name);
  		this.SetSocialSecurityNumber(ssn);
  	}
  }
Sicheres Codebeispiel

Secure pseudo

Sicher 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.
Präventions-Checkliste

How to prevent CWE-499

  • Implementation In Java, explicitly define final writeObject() to prevent serialization. This is the recommended solution. Define the writeObject() function to throw an exception explicitly denying serialization.
  • Implementation Make sure to prevent serialization of your objects.
Erkennungssignale

How to detect CWE-499

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 erkennt CWE-499 automatisch und öffnet in unter 60 Sekunden einen Fix-PR.

Codex Remedium scannt jeden Commit, identifiziert genau diese Schwachstelle und liefert einen reviewer-ready Pull Request mit dem Patch. Keine Tickets. Keine Hand-offs.

Häufig gestellte Fragen

Frequently asked questions

Was ist CWE-499?

This vulnerability occurs when a class containing sensitive information, such as credentials or personal data, is left serializable by default. Because the class does not explicitly prevent serialization, its internal data can be accessed and extracted by other parts of the application or external processes.

Wie gravierend ist CWE-499?

MITRE stuft die Exploit-Wahrscheinlichkeit als hoch ein — diese Schwachstelle wird aktiv in freier Wildbahn ausgenutzt und sollte priorisiert behoben werden.

Welche Sprachen oder Plattformen sind von CWE-499 betroffen?

MITRE lists the following affected platforms: Java.

Wie kann ich CWE-499 verhindern?

In Java, explicitly define final writeObject() to prevent serialization. This is the recommended solution. Define the writeObject() function to throw an exception explicitly denying serialization. Make sure to prevent serialization of your objects.

Wie erkennt und behebt Plexicus CWE-499?

Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-499 bei jedem Commit. Bei einem Treffer öffnet unser Codex-Remedium-Agent einen Fix-PR mit korrigiertem Code, Tests und einer einzeiligen Zusammenfassung für den Reviewer.

Wo erfahre ich mehr über CWE-499?

MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/499.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.

Verwandte Schwachstellen

Weaknesses related to CWE-499

CWE-668 Parent

Exposure of Resource to Wrong Sphere

This vulnerability occurs when an application unintentionally makes a resource accessible to users or systems that should not have…

CWE-1189 Sibling

Improper Isolation of Shared Resources on System-on-a-Chip (SoC)

This vulnerability occurs when a System-on-a-Chip (SoC) fails to properly separate shared hardware resources between secure (trusted) and…

CWE-1282 Sibling

Assumed-Immutable Data is Stored in Writable Memory

This vulnerability occurs when data that should be permanent and unchangeable—like a bootloader, device IDs, or one-time configuration…

CWE-1327 Sibling

Binding to an Unrestricted IP Address

This vulnerability occurs when software or a service is configured to bind to the IP address 0.0.0.0 (or :: in IPv6), which acts as a…

CWE-1331 Sibling

Improper Isolation of Shared Resources in Network On Chip (NoC)

This vulnerability occurs when a Network on Chip (NoC) fails to properly separate its internal, shared resources—like buffers, switches,…

CWE-134 Sibling

Use of Externally-Controlled Format String

This vulnerability occurs when a program uses a format string from an untrusted, external source (like user input, a network packet, or a…

CWE-200 Sibling

Exposure of Sensitive Information to an Unauthorized Actor

This weakness occurs when an application unintentionally reveals sensitive data to someone who shouldn't have access to it.

CWE-374 Sibling

Passing Mutable Objects to an Untrusted Method

This vulnerability occurs when a function receives a direct reference to mutable data, such as an object or array, instead of a safe copy…

CWE-375 Sibling

Returning a Mutable Object to an Untrusted Caller

This vulnerability occurs when a method directly returns a reference to its internal mutable data, allowing untrusted calling code to…

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