Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.
CWE-188 Base Draft
Reliance on Data/Memory Layout
This vulnerability occurs when software incorrectly assumes how data is structured in memory or within network packets, leading to unexpected behavior when those underlying layouts change.
Definition
What is CWE-188?
This vulnerability occurs when software incorrectly assumes how data is structured in memory or within network packets, leading to unexpected behavior when those underlying layouts change.
At the system level, memory layout is not universal. Different compilers, architectures, or platform updates can change how variables are ordered, aligned, or padded in memory. For example, one system might place two variables adjacent to each other, while another inserts space between them for performance alignment. If your code assumes a specific, fixed arrangement—like calculating offsets between variables—it will break when ported or run in a different environment, potentially reading corrupt data or causing crashes.
In network protocols, similar risks exist when parsing messages. Developers often use fixed offsets relative to known header fields to locate specific data. However, new protocol versions, optional extensions, or edge cases can introduce unexpected padding or reorder fields. This causes the software to misinterpret packet contents, treating one type of data (like a length field) as another (like payload data), which can lead to security flaws like information disclosure or denial of service.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-188
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 C
In this example function, the memory address of variable b is derived by adding 1 to the address of variable a. This derived address is then used to assign the value 0 to b.
void example() {
char a;
char b;
*(&a + 1) = 0;
} 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-188
- Implementation / Architecture and Design In flat address space situations, never allow computing memory addresses as offsets from another memory address.
- Architecture and Design Fully specify protocol layout unambiguously, providing a structured grammar (e.g., a compilable yacc grammar).
- Testing Testing: Test that the implementation properly handles each case in the protocol grammar.
Erkennungssignale
How to detect CWE-188
CWE-188
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-188?
Wie gravierend ist CWE-188?
Welche Sprachen oder Plattformen sind von CWE-188 betroffen?
Wie kann ich CWE-188 verhindern?
Wie erkennt und behebt Plexicus CWE-188?
Wo erfahre ich mehr über CWE-188?
Frequently asked questions
Was ist CWE-188?
This vulnerability occurs when software incorrectly assumes how data is structured in memory or within network packets, leading to unexpected behavior when those underlying layouts change.
Wie gravierend ist CWE-188?
MITRE stuft die Exploit-Wahrscheinlichkeit als niedrig ein — eine Ausnutzung ist selten, die Schwachstelle sollte aber dennoch behoben werden, sobald sie entdeckt wird.
Welche Sprachen oder Plattformen sind von CWE-188 betroffen?
MITRE lists the following affected platforms: C, C++.
Wie kann ich CWE-188 verhindern?
In flat address space situations, never allow computing memory addresses as offsets from another memory address. Fully specify protocol layout unambiguously, providing a structured grammar (e.g., a compilable yacc grammar).
Wie erkennt und behebt Plexicus CWE-188?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-188 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-188?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/188.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
Weaknesses related to CWE-188
CWE-1105 Parent
Insufficient Encapsulation of Machine-Dependent Functionality
This weakness occurs when an application relies on hardware-specific or platform-dependent features but fails to isolate that code from…
CWE-198 Child
Use of Incorrect Byte Ordering
This vulnerability occurs when software processes data from another system without considering byte order (endianness), such as big-endian…
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.