Ejecuta análisis estático (SAST) sobre el código buscando el patrón inseguro en el flujo de datos.
CWE-649 Base Incompleto
Reliance on Obfuscation or Encryption of Security-Relevant Inputs without Integrity Checking
This vulnerability occurs when an application uses obfuscation or encryption to hide security-sensitive data (like tokens or parameters) but fails to verify whether that data has been altered.…
Definición
What is CWE-649?
This vulnerability occurs when an application uses obfuscation or encryption to hide security-sensitive data (like tokens or parameters) but fails to verify whether that data has been altered. Without integrity checks, the system cannot detect if an attacker has tampered with these inputs.
Applications often hide or encrypt client-side data that influences server-side decisions, such as user permissions or system state. However, if the server only decodes or de-obfuscates this data without verifying its authenticity, an attacker can systematically guess or modify values to elevate privileges, access sensitive information, or alter application behavior. Obfuscation and weak encryption are designed for confidentiality, not integrity—they cannot prevent tampering.
To prevent this, developers must implement robust integrity checks like digital signatures or HMACs alongside any obfuscation or encryption. These mechanisms allow the server to confirm that the data hasn't been changed since it was originally issued. Relying solely on hiding data is insufficient; you must actively validate its trustworthiness before using it for security-critical operations.
Impacto en el mundo real
Real-world CVEs caused by CWE-649
-
An IPSec configuration does not perform integrity checking of the IPSec packet as the result of either not configuring ESP properly to support the integrity service or using AH improperly. In either case, the security gateway receiving the IPSec packet would not validate the integrity of the packet to ensure that it was not changed. Thus if the packets were intercepted the attacker could undetectably change some of the bits in the packets. The meaningful bit flipping was possible due to the known weaknesses in the CBC encryption mode. Since the attacker knew the structure of the packet, they were able (in one variation of the attack) to use bit flipping to change the destination IP of the packet to the destination machine controlled by the attacker. And so the destination security gateway would decrypt the packet and then forward the plaintext to the machine controlled by the attacker. The attacker could then read the original message. For instance if VPN was used with the vulnerable IPSec configuration the attacker could read the victim's e-mail. This vulnerability demonstrates the need to enforce the integrity service properly when critical data could be modified by an attacker. This problem might have also been mitigated by using an encryption mode that is not susceptible to bit flipping attacks, but the preferred mechanism to address this problem still remains message verification for integrity. While this attack focuses on the network layer and requires an entity that controls part of the communication path such as a router, the situation is not much different at the software level, where an attacker can modify tokens/parameters used by the application.
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 pseudo
MITRE no ha publicado un ejemplo de código para esta CWE. El patrón siguiente es ilustrativo — consulta Recursos para referencias canónicas.
// Example pattern — see MITRE for the canonical references.
function handleRequest(input) {
// Untrusted input flows directly into the sensitive sink.
return executeUnsafe(input);
} 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-649
- Architecture and Design Protect important client controllable tokens/parameters for integrity using PKI methods (i.e. digital signatures) or other means, and checks for integrity on the server side.
- Architecture and Design Repeated requests from a particular user that include invalid values of tokens/parameters (those that should not be changed manually by users) should result in the user account lockout.
- Architecture and Design Client side tokens/parameters should not be such that it would be easy/predictable to guess another valid state.
- Architecture and Design Obfuscation should not be relied upon. If encryption is used, it needs to be properly applied (i.e. proven algorithm and implementation, use padding, use random initialization vector, user proper encryption mode). Even with proper encryption where the ciphertext does not leak information about the plaintext or reveal its structure, compromising integrity is possible (although less likely) without the provision of the integrity service.
Señales de detección
How to detect CWE-649
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.
Plexicus detecta automáticamente CWE-649 y abre un PR de corrección en menos de 60 segundos.
Codex Remedium escanea cada commit, identifica esta debilidad concreta y entrega un pull request listo para revisión con el parche. Sin tickets. Sin traspasos.
Preguntas frecuentes ¿Qué es CWE-649?
¿Qué gravedad tiene CWE-649?
¿Qué lenguajes o plataformas se ven afectados por CWE-649?
¿Cómo puedo prevenir CWE-649?
¿Cómo detecta y corrige Plexicus CWE-649?
¿Dónde puedo aprender más sobre CWE-649?
Frequently asked questions
¿Qué es CWE-649?
This vulnerability occurs when an application uses obfuscation or encryption to hide security-sensitive data (like tokens or parameters) but fails to verify whether that data has been altered. Without integrity checks, the system cannot detect if an attacker has tampered with these inputs.
¿Qué gravedad tiene CWE-649?
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-649?
MITRE no ha especificado plataformas afectadas para esta CWE — puede aplicar a la mayoría de los stacks de aplicaciones.
¿Cómo puedo prevenir CWE-649?
Protect important client controllable tokens/parameters for integrity using PKI methods (i.e. digital signatures) or other means, and checks for integrity on the server side. Repeated requests from a particular user that include invalid values of tokens/parameters (those that should not be changed manually by users) should result in the user account lockout.
¿Cómo detecta y corrige Plexicus CWE-649?
El motor SAST de Plexicus detecta la firma de flujo de datos para CWE-649 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-649?
MITRE publica la definición canónica en https://cwe.mitre.org/data/definitions/649.html. También puedes consultar la documentación de OWASP y NIST para guías relacionadas.
Debilidades relacionadas
Weaknesses related to CWE-649
CWE-345 Padre
Insufficient Verification of Data Authenticity
This vulnerability occurs when an application fails to properly check where data comes from or confirm its legitimacy, allowing untrusted…
CWE-1293 Hermano
Missing Source Correlation of Multiple Independent Data
This vulnerability occurs when a system trusts a single source of data without verification, making it impossible to detect if that source…
CWE-346 Hermano
Origin Validation Error
This vulnerability occurs when an application fails to properly confirm the true origin of incoming data or communication, allowing…
CWE-347 Hermano
Improper Verification of Cryptographic Signature
This vulnerability occurs when an application fails to properly check the digital signature on data, or skips the verification step…
CWE-348 Hermano
Use of Less Trusted Source
This vulnerability occurs when a system has access to multiple sources for the same critical data, but it chooses to rely on the less…
CWE-349 Hermano
Acceptance of Extraneous Untrusted Data With Trusted Data
This vulnerability occurs when a system processes both trusted and untrusted data together, but fails to separate them. The application…
CWE-351 Hermano
Insufficient Type Distinction
This vulnerability occurs when an application fails to properly differentiate between different types of data or objects, leading to…
CWE-352 Hermano
Cross-Site Request Forgery (CSRF)
Cross-Site Request Forgery (CSRF) happens when a web application cannot reliably tell if a user actually intended to submit a request,…
CWE-353 Hermano
Missing Support for Integrity Check
This vulnerability occurs when a system uses a communication protocol that lacks built-in integrity verification, such as a checksum or…
Listo cuando tú lo estés
Deja de pagar por desarrollador.
Empieza a cerrar el bucle.
Plexicus es el ASPM nativo de IA que escanea, filtra, corrige, pentestea y explica — de forma autónoma. Desarrolladores ilimitados, repos ilimitados, acciones de IA de uso justo. Nivel gratuito real, €269/mo anual cuando estés listo.