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-321 Variant Draft
Use of Hard-coded Cryptographic Key
This vulnerability occurs when an application embeds a fixed, unchangeable cryptographic key directly within its source code or configuration files.
Definition
What is CWE-321?
This vulnerability occurs when an application embeds a fixed, unchangeable cryptographic key directly within its source code or configuration files.
Hard-coding cryptographic keys is a common but dangerous practice that undermines the security of encrypted data. Since the key is the same in every instance of the application and cannot be changed without modifying the code, an attacker who discovers the key (e.g., by inspecting the source code, binaries, or configuration files) can decrypt any sensitive data the application protects. This flaw effectively renders encryption useless, as the secret is no longer secret.
To fix this, developers should use secure key management systems that allow keys to be stored externally, rotated regularly, and accessed securely at runtime. While SAST tools can detect the hard-coded pattern, Plexicus uses AI to suggest the actual code fix—such as integrating with a secrets manager or environment variables—saving hours of manual refactoring and helping you enforce secure key handling across your entire application portfolio.
Auswirkungen in der Praxis
Real-world CVEs caused by CWE-321
-
Engineering Workstation uses hard-coded cryptographic keys that could allow for unathorized filesystem access and privilege escalation
-
Remote Terminal Unit (RTU) uses a hard-coded SSH private key that is likely to be used by default.
-
WiFi router service has a hard-coded encryption key, allowing root access
-
Communications / collaboration product has a hardcoded SSH private key, allowing access to root account
Wie Angreifer es ausnutzen
Angreiferpfad Schritt für Schritt
- 1
The following code examples attempt to verify a password using a hard-coded cryptographic key.
- 2
The cryptographic key is within a hard-coded string value that is compared to the password. It is likely that an attacker will be able to read the key and compromise the system.
- 3
In 2022, the OT:ICEFALL study examined products by 10 different Operational Technology (OT) vendors. The researchers reported 56 vulnerabilities and said that the products were "insecure by design" [REF-1283]. If exploited, these vulnerabilities often allowed adversaries to change how the products operated, ranging from denial of service to changing the code that the products executed. Since these products were often used in industries such as power, electrical, water, and others, there could even be safety implications.
- 4
Multiple vendors used hard-coded keys for critical functionality in their OT products.
Verwundbares Codebeispiel
Vulnerable C
The following code examples attempt to verify a password using a hard-coded cryptographic key.
int VerifyAdmin(char *password) {
if (strcmp(password,"68af404b513073584c4b6f22b6c63e6b")) {
printf("Incorrect Password!\n");
return(0);
}
printf("Entering Diagnostic Mode...\n");
return(1);
} 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-321
- Architecture and Design Prevention schemes mirror that of hard-coded password storage.
Erkennungssignale
How to detect CWE-321
CWE-321
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-321?
Wie gravierend ist CWE-321?
Welche Sprachen oder Plattformen sind von CWE-321 betroffen?
Wie kann ich CWE-321 verhindern?
Wie erkennt und behebt Plexicus CWE-321?
Wo erfahre ich mehr über CWE-321?
Frequently asked questions
Was ist CWE-321?
This vulnerability occurs when an application embeds a fixed, unchangeable cryptographic key directly within its source code or configuration files.
Wie gravierend ist CWE-321?
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-321 betroffen?
MITRE lists the following affected platforms: ICS/OT.
Wie kann ich CWE-321 verhindern?
Prevention schemes mirror that of hard-coded password storage.
Wie erkennt und behebt Plexicus CWE-321?
Die SAST-Engine von Plexicus erkennt die Datenfluss-Signatur von CWE-321 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-321?
MITRE veröffentlicht die kanonische Definition unter https://cwe.mitre.org/data/definitions/321.html. Für ergänzende Hinweise kannst du auch die OWASP- und NIST-Dokumentation heranziehen.
Verwandte Schwachstellen
Weaknesses related to CWE-321
CWE-798 Parent
Use of Hard-coded Credentials
This vulnerability occurs when software contains built-in, unchangeable authentication secrets like passwords or encryption keys within…
CWE-259 Sibling
Use of Hard-coded Password
This vulnerability occurs when an application embeds a password directly into its source code or configuration files. This hard-coded…
Ressourcen
Further reading
- MITRE — offizielle CWE-321 https://cwe.mitre.org/data/definitions/321.html
- The CLASP Application Security Process https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf
- OT:ICEFALL: The legacy of "insecure by design" and its implications for certifications and risk management https://www.forescout.com/resources/ot-icefall-report/
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.