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 Variante Borrador
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.
Definición
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.
Impacto en el mundo real
Real-world CVEs caused by CWE-321
-
Engineering Workstation uses hard-coded cryptographic keys that could allow for unathorized filesystem access and privilege escalation
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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
Cómo lo explotan los atacantes
Ruta del atacante paso a paso
- 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.
Ejemplo de código vulnerable
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);
} Ejemplo de código seguro
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.
Lista de prevención
How to prevent CWE-321
- Architecture and Design Prevention schemes mirror that of hard-coded password storage.
Señales de detección
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.
Preguntas frecuentes ¿Qué es CWE-321?
¿Qué gravedad tiene CWE-321?
¿Qué lenguajes o plataformas se ven afectados por CWE-321?
¿Cómo puedo prevenir CWE-321?
¿Cómo detecta y corrige Plexicus CWE-321?
¿Dónde puedo aprender más sobre CWE-321?
Frequently asked questions
¿Qué es CWE-321?
This vulnerability occurs when an application embeds a fixed, unchangeable cryptographic key directly within its source code or configuration files.
¿Qué gravedad tiene CWE-321?
MITRE califica la probabilidad de explotación como Alta — esta debilidad se explota activamente en la práctica y debe priorizarse para su remediación.
¿Qué lenguajes o plataformas se ven afectados por CWE-321?
MITRE lists the following affected platforms: ICS/OT.
¿Cómo puedo prevenir CWE-321?
Prevention schemes mirror that of hard-coded password storage.
¿Cómo detecta y corrige Plexicus CWE-321?
El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-321 en cada commit. Cuando hay coincidencia, nuestro agente Codex Remedium abre un PR de corrección con el código corregido, las pruebas y un resumen de una línea para el revisor.
¿Dónde puedo aprender más sobre CWE-321?
MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/321.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.
Debilidades relacionadas
Weaknesses related to CWE-321
CWE-798 Padre
Use of Hard-coded Credentials
This vulnerability occurs when software contains built-in, unchangeable authentication secrets like passwords or encryption keys within…
CWE-259 Hermano
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…
Recursos
Further reading
- MITRE — CWE-321 oficial 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/
¿Listo para validar lo que importa?
Listo para validar lo que importa.
Plexicus es Proof-Driven AppSec: hallazgos validados, comprensión contextual y remediación revisada — anclada en evidencia, acotada contigo.