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-495 Variant Draft
Private Data Structure Returned From A Public Method
This vulnerability occurs when a public method directly returns a reference to a private, internal data structure. Because the reference is live, external callers can bypass intended controls and…
Definition
What is CWE-495?
This vulnerability occurs when a public method directly returns a reference to a private, internal data structure. Because the reference is live, external callers can bypass intended controls and modify the data unexpectedly, corrupting the application's state.
This flaw breaks a core principle of encapsulation in object-oriented design. The private data structure—like an array, collection, or object—is meant to be managed solely by the class's own methods. By handing out a direct reference, you allow external code to add, remove, or alter elements without validation, leading to data corruption, security bypasses, or crashes that are difficult to debug. The fix is to return either a copy of the data (defensive copying) or an immutable view, ensuring the internal state remains protected.
Identifying every instance of this pattern across a large codebase can be tedious. While SAST tools can flag the risky return statements, Plexicus uses AI to analyze the context and automatically suggest the correct remediation—such as implementing `Collections.unmodifiableList()` in Java or a slice copy in Go—saving developers hours of manual refactoring and ensuring consistent fixes.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-495
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, a public method in a Java class returns a reference to a private array. Given that arrays in Java are mutable, any modifications made to the returned reference would be reflected in the original private array.
private String[] colors;
public String[] getColors() {
return colors;
} 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-495
- Implementation Declare the method private.
- Implementation Clone the member data and keep an unmodified version of the data private to the object.
- Implementation Use public setter methods that govern how a private member can be modified.
Erkennungssignale
How to detect CWE-495
CWE-495
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-495?
Wie gravierend ist CWE-495?
Welche Sprachen oder Plattformen sind von CWE-495 betroffen?
Wie kann ich CWE-495 verhindern?
Wie erkennt und behebt Plexicus CWE-495?
Wo erfahre ich mehr über CWE-495?
Frequently asked questions
Was ist CWE-495?
This vulnerability occurs when a public method directly returns a reference to a private, internal data structure. Because the reference is live, external callers can bypass intended controls and modify the data unexpectedly, corrupting the application's state.
Wie gravierend ist CWE-495?
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-495 betroffen?
MITRE lists the following affected platforms: C, C++, Java, C#.
Wie kann ich CWE-495 verhindern?
Declare the method private. Clone the member data and keep an unmodified version of the data private to the object.
Wie erkennt und behebt Plexicus CWE-495?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-495 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-495?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/495.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
Weaknesses related to CWE-495
CWE-664 Parent
Improper Control of a Resource Through its Lifetime
This vulnerability occurs when software fails to properly manage a resource throughout its entire lifecycle—from creation and active use…
CWE-118 Sibling
Incorrect Access of Indexable Resource ('Range Error')
This vulnerability occurs when software fails to properly check the boundaries of an indexed resource, like an array, buffer, or file,…
CWE-1229 Sibling
Creation of Emergent Resource
This vulnerability occurs when a system's normal operations unintentionally create new, exploitable resources that attackers can use to…
CWE-1250 Sibling
Improper Preservation of Consistency Between Independent Representations of Shared State
This vulnerability occurs when a system with multiple independent components (like distributed services or separate hardware units) each…
CWE-1329 Sibling
Reliance on Component That is Not Updateable
This vulnerability occurs when a product depends on a component that cannot be updated or patched to fix security flaws or critical bugs.
CWE-221 Sibling
Information Loss or Omission
This weakness occurs when an application fails to log critical security events or records them inaccurately, which can misguide security…
CWE-372 Sibling
Incomplete Internal State Distinction
This vulnerability occurs when an application fails to accurately track its own operational state. The system incorrectly assumes it's in…
CWE-400 Sibling
Uncontrolled Resource Consumption
This vulnerability occurs when an application fails to properly manage a finite resource, allowing an attacker to exhaust it and cause a…
CWE-404 Sibling
Improper Resource Shutdown or Release
This vulnerability occurs when a program fails to properly close or release a system resource—like a file handle, database connection, or…
Ressourcen
Further reading
- MITRE — offizielle CWE-495 https://cwe.mitre.org/data/definitions/495.html
- Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors https://samate.nist.gov/SSATTM_Content/papers/Seven%20Pernicious%20Kingdoms%20-%20Taxonomy%20of%20Sw%20Security%20Errors%20-%20Tsipenyuk%20-%20Chess%20-%20McGraw.pdf
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.