CWE-572 Variante Borrador

Call to Thread run() instead of start()

This vulnerability occurs when a program incorrectly calls a thread's `run()` method directly, instead of using the `start()` method. This mistake causes the thread's code to execute within the…

Definición

What is CWE-572?

This vulnerability occurs when a program incorrectly calls a thread's `run()` method directly, instead of using the `start()` method. This mistake causes the thread's code to execute within the caller's current thread, bypassing the creation of a new, concurrent thread of execution.
Calling `run()` directly is almost always a programming error. The developer's intent is to launch new, concurrent operations using the `Thread` class. However, by calling `run()`, the code within that method simply executes as a normal function call in the existing thread. This defeats the entire purpose of using threads, leading to sequential execution and potential performance issues, as no true parallelism or concurrency is achieved. The core issue is a misunderstanding of the Java threading model. The `start()` method is responsible for the native OS-level thread creation and scheduling, which then automatically calls the `run()` method in the new thread context. Bypassing `start()` means the `run()` method's code runs with the stack and context of the parent thread, which can cause unexpected behavior, block the UI, or break assumptions about thread-local data and synchronization.
Impacto en el mundo real

Real-world CVEs caused by CWE-572

Todavía no hay CVEs públicos enlazados a esta CWE en el catálogo de MITRE.

Cómo lo explotan los atacantes

Ruta del atacante paso a paso

  1. 1

    Identifica una ruta de código que maneje entrada no confiable sin validación.

  2. 2

    Crea un payload que ejercite el comportamiento inseguro — inyección, traversal, overflow o abuso de lógica.

  3. 3

    Envía el payload a través de una solicitud normal y observa la reacción de la aplicación.

  4. 4

    Itera hasta que la respuesta filtre datos, ejecute código del atacante o escale privilegios.

Ejemplo de código vulnerable

Vulnerable Java

The following excerpt from a Java program mistakenly calls run() instead of start().

Vulnerable Java
Thread thr = new Thread() {
  	public void run() {
  		...
  	}
  };
  thr.run();
Ejemplo de código seguro

Secure pseudo

Seguro 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-572

  • Implementation Use the start() method instead of the run() method.
Señales de detección

How to detect CWE-572

Automated Static Analysis High

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-572

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

Frequently asked questions

¿Qué es CWE-572?

This vulnerability occurs when a program incorrectly calls a thread's `run()` method directly, instead of using the `start()` method. This mistake causes the thread's code to execute within the caller's current thread, bypassing the creation of a new, concurrent thread of execution.

¿Qué gravedad tiene CWE-572?

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-572?

MITRE lists the following affected platforms: Java.

¿Cómo puedo prevenir CWE-572?

Use the start() method instead of the run() method.

¿Cómo detecta y corrige Plexicus CWE-572?

El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-572 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-572?

MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/572.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.

¿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.

Calificación

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SAMPLE HANDOVER · ILLUSTRATIVE

Sample evidence handover

A trimmed view of what your team receives at the end of an AI Swarm Pentest engagement. Real engagements include full technical evidence, executive narrative, and a remediation plan.

VALIDATED FINDING Evidence attached

Server-Side Request Forgery in webhooks/receiver

demo-project/sample-app · src/webhooks/receiver.py:42

SeverityHigh CVSS 3.18.6 Priority79 Confirmedvia replay

Untrusted caller-supplied URLs reach an internal egress without an allowlist. Replayed in a sandbox against a fresh authorized target — the same control was validated to fail twice.

REVIEWER-READY REMEDIATION Merge-ready PR

Validate the target URL against an allowlist of permitted hostnames. Reject private/internal IP ranges. Enforce HTTPS only.

plexicus/remediation/webhooks-ssrf 3 changed · 0 new files
42resp = requests.get(target_url)
42+if not is_allowed_host(target_url):
43+  raise WebhookRejected(target_url)
44+resp = requests.get(target_url, timeout=5)
Every engagement hands over:
  • Executive briefing
  • Validated findings list
  • Merge-ready PRs
  • Compliance mapping (NIS2 · DORA · CRA)
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