Ejecuta análisis estático (SAST) sobre el código buscando el patrón inseguro en el flujo de datos.
CWE-341 Base Borrador
Predictable from Observable State
This vulnerability occurs when an attacker can guess or deduce sensitive values, like random numbers or identifiers, by observing predictable system or network characteristics such as timestamps,…
Definición
What is CWE-341?
This vulnerability occurs when an attacker can guess or deduce sensitive values, like random numbers or identifiers, by observing predictable system or network characteristics such as timestamps, process IDs, or other public information.
This weakness undermines security by making supposedly random or secret values guessable. Instead of being truly unpredictable, these values follow a pattern or are derived from observable system state, like the current time, incrementing counters, or publicly accessible identifiers. Attackers can exploit this to predict session tokens, cryptographic nonces, or temporary file names, leading to unauthorized access or data breaches.
To prevent this, developers must ensure that all security-critical values are generated using cryptographically secure random number generators (CSPRNGs) designed to resist prediction. Avoid using predictable sources like system time, process IDs, or unseeded pseudo-random functions for secrets, tokens, or initialization vectors. Always validate that randomness sources are appropriate for the security context of the feature you are building.
Impacto en el mundo real
Real-world CVEs caused by CWE-341
-
Mail server stores private mail messages with predictable filenames in a world-executable directory, which allows local users to read private mailing list archives.
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PRNG allows attackers to use the output of small PRNG requests to determine the internal state information, which could be used by attackers to predict future pseudo-random numbers.
-
DNS resolver library uses predictable IDs, which allows a local attacker to spoof DNS query results.
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MFV. predictable filename and insecure permissions allows file modification to execute SQL queries.
Cómo lo explotan los atacantes
Ruta del atacante paso a paso
- 1
This code generates a unique random identifier for a user's session.
- 2
Because the seed for the PRNG is always the user's ID, the session ID will always be the same. An attacker could thus predict any user's session ID and potentially hijack the session.
- 3
This example also exhibits a Small Seed Space (CWE-339).
Ejemplo de código vulnerable
Vulnerable PHP
This code generates a unique random identifier for a user's session.
function generateSessionID($userID){
srand($userID);
return rand();
} 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-341
- Implementation Increase the entropy used to seed a PRNG.
- Architecture and Design / Requirements Use products or modules that conform to FIPS 140-2 [REF-267] to avoid obvious entropy problems. Consult FIPS 140-2 Annex C ("Approved Random Number Generators").
- Implementation Use a PRNG that periodically re-seeds itself using input from high-quality sources, such as hardware devices with high entropy. However, do not re-seed too frequently, or else the entropy source might block.
Señales de detección
How to detect CWE-341
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-341
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-341?
¿Qué gravedad tiene CWE-341?
¿Qué lenguajes o plataformas se ven afectados por CWE-341?
¿Cómo puedo prevenir CWE-341?
¿Cómo detecta y corrige Plexicus CWE-341?
¿Dónde puedo aprender más sobre CWE-341?
Frequently asked questions
¿Qué es CWE-341?
This vulnerability occurs when an attacker can guess or deduce sensitive values, like random numbers or identifiers, by observing predictable system or network characteristics such as timestamps, process IDs, or other public information.
¿Qué gravedad tiene CWE-341?
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-341?
MITRE no ha especificado plataformas afectadas para esta CWE — puede aplicar a la mayoría de los stacks de aplicaciones.
¿Cómo puedo prevenir CWE-341?
Increase the entropy used to seed a PRNG. Use products or modules that conform to FIPS 140-2 [REF-267] to avoid obvious entropy problems. Consult FIPS 140-2 Annex C ("Approved Random Number Generators").
¿Cómo detecta y corrige Plexicus CWE-341?
El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-341 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-341?
MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/341.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.
Debilidades relacionadas
Weaknesses related to CWE-341
CWE-340 Padre
Generation of Predictable Numbers or Identifiers
This vulnerability occurs when a system creates numbers or identifiers that are too easy to guess, undermining security mechanisms that…
CWE-342 Hermano
Predictable Exact Value from Previous Values
This vulnerability occurs when a system uses a predictable sequence for generating values, allowing an attacker to accurately guess future…
CWE-343 Hermano
Predictable Value Range from Previous Values
This vulnerability occurs when a system's random number generator produces values that, after observing previous outputs, allow an…
¿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.