Ejecuta análisis estático (SAST) sobre el código buscando el patrón inseguro en el flujo de datos.
CWE-221 Clase Incompleto
Information Loss or Omission
This weakness occurs when an application fails to log critical security events or records them inaccurately, which can misguide security decisions and hinder incident investigation.
Definición
What is CWE-221?
This weakness occurs when an application fails to log critical security events or records them inaccurately, which can misguide security decisions and hinder incident investigation.
When a system doesn't capture key details like authentication failures, access violations, or input errors, security teams lose the visibility needed to detect and respond to attacks. This omission creates blind spots, making it difficult to understand an attack's origin, method, and impact, ultimately weakening your security posture.
This problem can also be a side effect of another vulnerability. For instance, a severe issue like a buffer overflow might cause a program to crash abruptly before it has a chance to write any log entry about the anomalous event. This means the root cause remains hidden, complicating forensic analysis and delaying the fix for the underlying flaw.
Impacto en el mundo real
Real-world CVEs caused by CWE-221
-
Web browser's filename selection dialog only shows the beginning portion of long filenames, which can trick users into launching executables with dangerous extensions.
-
application server does not log complete URI of a long request (truncation).
-
Login attempts are not recorded if the user disconnects before the maximum number of tries.
-
Attacker performs malicious actions on a hard link to a file, obscuring the real target file.
-
Product does not warn user when document contains certain dangerous functions or macros.
Cómo lo explotan los atacantes
Ruta del atacante paso a paso
- 1
Identifica una ruta de código que maneje entrada no confiable sin validación.
- 2
Crea un payload que ejercite el comportamiento inseguro — inyección, traversal, overflow o abuso de lógica.
- 3
Envía el payload a través de una solicitud normal y observa la reacción de la aplicación.
- 4
Itera hasta que la respuesta filtre datos, ejecute código del atacante o escale privilegios.
Ejemplo de código vulnerable
Vulnerable PHP
This code logs suspicious multiple login attempts.
function login($userName,$password){
if(authenticate($userName,$password)){
return True;
}
else{
incrementLoginAttempts($userName);
if(recentLoginAttempts($userName) > 5){
writeLog("Failed login attempt by User: " . $userName . " at " + date('r') );
}
}
} 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-221
- Architecture Use safe-by-default frameworks and APIs that prevent the unsafe pattern from being expressible.
- Implementation Validate input at trust boundaries; use allowlists, not denylists.
- Implementation Apply the principle of least privilege to credentials, file paths, and runtime permissions.
- Testing Cover this weakness in CI: SAST rules + targeted unit tests for the data flow.
- Operation Monitor logs for the runtime signals listed in the next section.
Señales de detección
How to detect CWE-221
Ejecuta pruebas dinámicas de seguridad de aplicaciones (DAST) contra el endpoint en vivo.
Vigila los logs en tiempo de ejecución para detectar trazas de excepción inusuales, entradas malformadas o intentos de bypass de autorización.
Revisión de código: marca cualquier código nuevo que maneje entrada desde esta superficie sin usar los helpers validados del framework.
CWE-221
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-221?
¿Qué gravedad tiene CWE-221?
¿Qué lenguajes o plataformas se ven afectados por CWE-221?
¿Cómo puedo prevenir CWE-221?
¿Cómo detecta y corrige Plexicus CWE-221?
¿Dónde puedo aprender más sobre CWE-221?
Frequently asked questions
¿Qué es CWE-221?
This weakness occurs when an application fails to log critical security events or records them inaccurately, which can misguide security decisions and hinder incident investigation.
¿Qué gravedad tiene CWE-221?
MITRE no ha publicado una calificación de probabilidad de explotación para esta debilidad. Trátala como de impacto medio hasta que tu modelo de amenazas demuestre lo contrario.
¿Qué lenguajes o plataformas se ven afectados por CWE-221?
MITRE no ha especificado plataformas afectadas para esta CWE — puede aplicar a la mayoría de los stacks de aplicaciones.
¿Cómo puedo prevenir CWE-221?
Use safe-by-default frameworks, validate untrusted input at trust boundaries, and apply the principle of least privilege. Cover the data-flow signature in CI with SAST.
¿Cómo detecta y corrige Plexicus CWE-221?
El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-221 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-221?
MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/221.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.
Debilidades relacionadas
Weaknesses related to CWE-221
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CWE-118 Hermano
Incorrect Access of Indexable Resource ('Range Error')
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CWE-1229 Hermano
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 Hermano
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 Hermano
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-372 Hermano
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 Hermano
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 Hermano
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…
CWE-410 Hermano
Insufficient Resource Pool
This vulnerability occurs when a system's resource pool is too small to handle maximum usage. Attackers can exploit this by making a high…
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Listo para validar lo que importa.
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