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.)
CWE-607 Variant Draft
Public Static Final Field References Mutable Object
This vulnerability occurs when a class exposes a public or protected static final field that points to a changeable object. Because the field's reference is constant but the object itself is not,…
Definition
What is CWE-607?
This vulnerability occurs when a class exposes a public or protected static final field that points to a changeable object. Because the field's reference is constant but the object itself is not, malicious code or even accidental code in other packages can modify the object's contents, violating the intended immutability.
The core issue is a misunderstanding of the `final` keyword in Java and similar languages. When applied to an object reference, `final` only guarantees that the reference itself cannot be reassigned to point to a different object. It does not protect the internal state of the object that the reference points to. If that object is mutable—like an array, a collection, or a custom class with public setters—its data can be freely altered, even through the `static final` field.
To prevent this, developers must ensure true immutability. This involves either assigning the static final field to an inherently immutable object (like a `String` or a boxed primitive) or defensively wrapping mutable objects. For collections, use `Collections.unmodifiableList()`, `Map.copyOf()`, or similar methods to create an unmodifiable view or a deep copy before assignment. This practice encapsulates the mutable data and enforces the read-only intent of the public static field.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-607
Bisher sind in MITREs Katalog keine öffentlichen CVE-Referenzen mit dieser CWE verknüpft.
Wie Angreifer es ausnutzen
Angreiferpfad Schritt für Schritt
- 1
Identifiziere einen Codepfad, der nicht vertrauenswürdige Eingaben ohne Validierung verarbeitet.
- 2
Erzeuge eine Payload, die das unsichere Verhalten auslöst — Injection, Traversal, Overflow oder Logik-Missbrauch.
- 3
Liefere die Payload über einen normalen Request aus und beobachte die Reaktion der Anwendung.
- 4
Iteriere, bis die Antwort Daten preisgibt, Angreifer-Code ausführt oder Berechtigungen eskaliert.
Verwundbares Codebeispiel
Vulnerable Java
Here, an array (which is inherently mutable) is labeled public static final.
public static final String[] USER_ROLES; Sicheres Codebeispiel
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.
Präventions-Checkliste
How to prevent CWE-607
- Implementation Protect mutable objects by making them private. Restrict access to the getter and setter as well.
Erkennungssignale
How to detect CWE-607
CWE-607
Don't catalog this weakness. Prove it's reachable.
Plexicus turns CWE catalogs into evidence: every CWE-pattern is matched against your real code graph, reach is proven on a sandbox clone, and verified findings ship as reviewed PRs.
Häufig gestellte Fragen Was ist CWE-607?
Wie gravierend ist CWE-607?
Welche Sprachen oder Plattformen sind von CWE-607 betroffen?
Wie kann ich CWE-607 verhindern?
Wie erkennt und behebt Plexicus CWE-607?
Wo erfahre ich mehr über CWE-607?
Frequently asked questions
Was ist CWE-607?
This vulnerability occurs when a class exposes a public or protected static final field that points to a changeable object. Because the field's reference is constant but the object itself is not, malicious code or even accidental code in other packages can modify the object's contents, violating the intended immutability.
Wie gravierend ist CWE-607?
MITRE hat für diese Schwachstelle keine Exploit-Wahrscheinlichkeit veröffentlicht. Behandle sie als mittlere Auswirkung, bis dein Threat Model anderes belegt.
Welche Sprachen oder Plattformen sind von CWE-607 betroffen?
MITRE lists the following affected platforms: Java.
Wie kann ich CWE-607 verhindern?
Protect mutable objects by making them private. Restrict access to the getter and setter as well.
Wie erkennt und behebt Plexicus CWE-607?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-607 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-607?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/607.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
Weaknesses related to CWE-607
CWE-471 Parent
Modification of Assumed-Immutable Data (MAID)
This vulnerability occurs when an application fails to protect data it assumes cannot be changed, allowing an attacker to alter it.
CWE-472 Sibling
External Control of Assumed-Immutable Web Parameter
This vulnerability occurs when a web application incorrectly trusts data that appears to be fixed or hidden from the user, such as values…
CWE-473 Sibling
PHP External Variable Modification
This vulnerability occurs when a PHP application fails to properly validate or sanitize variables that originate from outside the…
Ressourcen
Further reading
Bereit, das Wesentliche zu validieren?
Bereit zu validieren, was zählt.
Plexicus ist Proof-Driven AppSec: validierte Funde, kontextuelles Verständnis und geprüfte Remediation — in Evidenz verankert, mit Ihnen gescoped.