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CWE-454 Base Draft
External Initialization of Trusted Variables or Data Stores
This vulnerability occurs when an application sets up its critical internal variables or storage systems using data from untrusted, external sources that an attacker could control.
Definition
What is CWE-454?
This vulnerability occurs when an application sets up its critical internal variables or storage systems using data from untrusted, external sources that an attacker could control.
A secure system should be cautious about trusting any data that originates from outside its own controlled environment. When core application variables or data stores—like configuration flags, security tokens, or internal state trackers—are populated with user-supplied or externally-provided values, attackers can feed them malicious data. This allows them to manipulate the application's logic from the very start, often leading to severe security breaches.
In practice, this means developers must ensure that all trusted variables are initialized with hard-coded values, secure internal processes, or rigorously validated data. Relying on external inputs for initialization, even if those inputs are later checked, creates a dangerous window where the system's foundational state is compromised. Always establish critical internal state independently, before processing any untrusted data.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-454
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WordPress module sets internal variables based on external inputs, allowing false reporting of the number of views
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Does not clear dangerous environment variables, enabling symlink attack.
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Specify alternate configuration directory in environment variable, enabling untrusted path.
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Dangerous environment variable not cleansed.
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Specify arbitrary modules using environment variable.
Wie Angreifer es ausnutzen
Angreiferpfad Schritt für Schritt
- 1
In the Java example below, a system property controls the debug level of the application.
- 2
If an attacker is able to modify the system property, then it may be possible to coax the application into divulging sensitive information by virtue of the fact that additional debug information is printed/exposed as the debug level increases.
- 3
This code checks the HTTP POST request for a debug switch, and enables a debug mode if the switch is set.
- 4
Any user can activate the debug mode, gaining administrator privileges. An attacker may also use the information printed by the phpinfo() function to further exploit the system. .
- 5
This example also exhibits Information Exposure Through Debug Information (CWE-215)
Verwundbares Codebeispiel
Vulnerable Java
In the Java example below, a system property controls the debug level of the application.
int debugLevel = Integer.getInteger("com.domain.application.debugLevel").intValue(); 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-454
- Implementation A product system should be reluctant to trust variables that have been initialized outside of its trust boundary. Ensure adequate checking (e.g. input validation) is performed when relying on input from outside a trust boundary.
- Architecture and Design Avoid any external control of variables. If necessary, restrict the variables that can be modified using an allowlist, and use a different namespace or naming convention if possible.
Erkennungssignale
How to detect CWE-454
Führe dynamische Application-Security-Tests gegen den Live-Endpoint aus.
Beobachte Runtime-Logs auf ungewöhnliche Exception-Traces, fehlerhafte Eingaben oder Versuche, Autorisierung zu umgehen.
Code Review: Markiere jeden neuen Code, der Eingaben von dieser Oberfläche ohne validierte Framework-Helper verarbeitet.
CWE-454
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-454?
Wie gravierend ist CWE-454?
Welche Sprachen oder Plattformen sind von CWE-454 betroffen?
Wie kann ich CWE-454 verhindern?
Wie erkennt und behebt Plexicus CWE-454?
Wo erfahre ich mehr über CWE-454?
Frequently asked questions
Was ist CWE-454?
This vulnerability occurs when an application sets up its critical internal variables or storage systems using data from untrusted, external sources that an attacker could control.
Wie gravierend ist CWE-454?
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-454 betroffen?
MITRE lists the following affected platforms: PHP.
Wie kann ich CWE-454 verhindern?
A product system should be reluctant to trust variables that have been initialized outside of its trust boundary. Ensure adequate checking (e.g. input validation) is performed when relying on input from outside a trust boundary. Avoid any external control of variables. If necessary, restrict the variables that can be modified using an allowlist, and use a different namespace or naming convention if possible.
Wie erkennt und behebt Plexicus CWE-454?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-454 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-454?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/454.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
Weaknesses related to CWE-454
CWE-1419 Parent
Incorrect Initialization of Resource
This weakness occurs when a system fails to properly set up a resource during its creation, leaving it in an unstable, incorrect, or…
CWE-1051 Sibling
Initialization with Hard-Coded Network Resource Configuration Data
This vulnerability occurs when software uses fixed, hard-coded values—like IP addresses, domain names, or URLs—to identify network…
CWE-1052 Sibling
Excessive Use of Hard-Coded Literals in Initialization
This weakness occurs when software initializes variables or data structures using hard-coded values (like strings, file paths, or network…
CWE-1188 Sibling
Initialization of a Resource with an Insecure Default
This vulnerability occurs when software uses an insecure default setting or value for a resource, assuming an administrator will change it…
CWE-1221 Sibling
Incorrect Register Defaults or Module Parameters
This vulnerability occurs when hardware description language (HDL) code sets insecure default values for hardware registers or…
CWE-456 Peer
Missing Initialization of a Variable
This vulnerability occurs when a program uses a variable before giving it a starting value, causing the software to rely on unpredictable…
Ressourcen
Further reading
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