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CVE-2021-35395

Estado: AnalizadaCrítica (9.8)⚠ Explotación activa💥 Exploit

Realtek Jungle SDK version v2.x up to v3.4.14B provides an HTTP web server exposing a management interface that can be used to configure the access point. Two versions of this management interface exists: one based on Go-Ahead named webs and another based on Boa named boa. Both of them are affected by these vulnerabilities.

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Specifically, these binaries are vulnerable to the following issues: - stack buffer overflow in formRebootCheck due to unsafe copy of submit-url parameter - stack buffer overflow in formWsc due to unsafe copy of submit-url parameter - stack buffer overflow in formWlanMultipleAP due to unsafe copy of submit-url parameter - stack buffer overflow in formWlSiteSurvey due to unsafe copy of ifname parameter - stack buffer overflow in formStaticDHCP due to unsafe copy of hostname parameter - stack buffer overflow in formWsc due to unsafe copy of 'peerPin' parameter - arbitrary command execution in formSysCmd via the sysCmd parameter - arbitrary command injection in formWsc via the 'peerPin' parameter Exploitability of identified issues will differ based on what the end vendor/manufacturer did with the Realtek SDK webserver. Some vendors use it as-is, others add their own authentication implementation, some kept all the features from the server, some remove some of them, some inserted their own set of features. However, given that Realtek SDK implementation is full of insecure calls and that developers tends to re-use those examples in their custom code, any binary based on Realtek SDK webserver will probably contains its own set of issues on top of the Realtek ones (if kept). Successful exploitation of these issues allows remote attackers to gain arbitrary code execution on the device.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

CISA KEV — explotada activamente

💥 Exploits públicos

Hay código de explotación o plantillas de detección públicos. No es lo mismo que explotación activa confirmada (KEV), pero aumenta el riesgo: parchee con prioridad.

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vector AV:N/AC:L/PR:N/UI:N indica explotación remota sin autenticación (T1190). Desbordamientos de pila y ejecución arbitraria de comandos en el servidor web expuesto (sysCmd, command injection) permiten RCE. Impacto confirmado en descripción: 'arbitrary code execution'.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network TrafficVulnerability ScanningRestrict Web-Based ContentPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over Network

Tecnologías afectadas (1)

Realtek — Rtl819x Jungle Software Development KIT

CWE

Referencias

JSON original (NVD)

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      "value": "Realtek Jungle SDK version v2.x up to v3.4.14B provides an HTTP web server exposing a management interface that can be used to configure the access point. Two versions of this management interface exists: one based on Go-Ahead named webs and another based on Boa named boa. Both of them are affected by these vulnerabilities. Specifically, these binaries are vulnerable to the following issues: - stack buffer overflow in formRebootCheck due to unsafe copy of submit-url parameter - stack buffer overflow in formWsc due to unsafe copy of submit-url parameter - stack buffer overflow in formWlanMultipleAP due to unsafe copy of submit-url parameter - stack buffer overflow in formWlSiteSurvey due to unsafe copy of ifname parameter - stack buffer overflow in formStaticDHCP due to unsafe copy of hostname parameter - stack buffer overflow in formWsc due to unsafe copy of 'peerPin' parameter - arbitrary command execution in formSysCmd via the sysCmd parameter - arbitrary command injection in formWsc via the 'peerPin' parameter Exploitability of identified issues will differ based on what the end vendor/manufacturer did with the Realtek SDK webserver. Some vendors use it as-is, others add their own authentication implementation, some kept all the features from the server, some remove some of them, some inserted their own set of features. However, given that Realtek SDK implementation is full of insecure calls and that developers tends to re-use those examples in their custom code, any binary based on Realtek SDK webserver will probably contains its own set of issues on top of the Realtek ones (if kept). Successful exploitation of these issues allows remote attackers to gain arbitrary code execution on the device."
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      "value": "Realtek Jungle SDK versiones v2.x hasta v3.4.14B, proporciona un servidor web HTTP que expone una interfaz de administración que puede ser usada para configurar el punto de acceso. Se presentan dos versiones de esta interfaz de administración: una basada en Go-Ahead denominada webs y otra basada en Boa denominada boa. Ambas están afectadas por estas vulnerabilidades. Específicamente, estos binarios son vulnerables a los siguientes problemas - desbordamiento del búfer de la pila en formRebootCheck debido a una copia no segura del parámetro submit-url - desbordamiento del búfer de la pila en formWsc debido a una copia no segura del parámetro submit-url - desbordamiento del búfer de la pila en formWlanMultipleAP debido a una copia no segura del parámetro submit-url - desbordamiento del búfer de la pila en formWlSiteSurvey debido a una copia no segura del parámetro ifname - desbordamiento del búfer de la pila  en formStaticDHCP debido a una copia no segura del parámetro hostname - desbordamiento del buffer de la pila en formWsc debido a una copia no segura del parámetro \"peerPin\" - ejecución arbitraria de comandos en formSysCmd por medio del parámetro sysCmd - inyección arbitraria de comandos en formWsc por medio del parámetro \"peerPin\". Una Explotación de los problemas identificados variará en función de lo que el proveedor/fabricante final haya hecho con el servidor web del SDK de Realtek. Algunos vendedores lo usan tal cual, otros añaden su propia implementación de autenticación, algunos mantienen todas las funcionalidades del servidor, otros eliminan algunas de ellas, otros insertan su propio conjunto de características. Sin embargo, dado que la implementación del SDK de Realtek está llena de llamadas no seguras y que los desarrolladores tienden a reusar esos ejemplos en su código personalizado, cualquier binario basado en el servidor web del SDK de Realtek probablemente contenga su propio conjunto de problemas además de los de Realtek (si se mantienen). Una explotación con éxito de estos problemas permite a atacantes remotos obtener una ejecución de código arbitrario en el dispositivo."
    }
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  "lastModified": "2026-06-17T03:57:29.367",
  "cisaActionDue": "2021-11-17",
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