CVE-2021-35394
Realtek Jungle SDK version v2.x up to v3.4.14B provides a diagnostic tool called 'MP Daemon' that is usually compiled as 'UDPServer' binary. The binary is affected by multiple memory corruption vulnerabilities and an arbitrary command injection vulnerability that can be exploited by remote unauthenticated attackers.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 9.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 100%
- Percentil entre todas las CVEs puntuadas: 100
- Fecha de la puntuación: 4/10/2026
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
- Añadida al catálogo: 10/12/2021
- Plazo de remediación: 24/12/2021
- Uso conocido en ransomware: Unknown
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access95 % - Impacto principal
T1059Command and Scripting Interpreterexecution90 % - Impacto secundario
T1499.004Application or System Exploitationimpact70 %
Vulnerabilidad remota sin autenticación (AV:N/PR:N) en herramienta expuesta (UDPServer). Command injection explícita permite ejecución de comandos. Impact crítico (C:H/I:H/A:H) sugiere DoS mediante corrupción de memoria.
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
Tecnologías afectadas (1)
CWE
- NVD-CWE-Other
- CWE-78
Referencias
- https://www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain
- https://www.realtek.com/en/cu-1-en/cu-1-taiwan-en
- https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2021-35392_35395.pdf
- https://www.securityfocus.com/archive/1/534765
- https://www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain
- https://www.realtek.com/en/cu-1-en/cu-1-taiwan-en
- https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2021-35392_35395.pdf
- https://www.securityfocus.com/archive/1/534765
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35394
JSON original (NVD)
Mostrar
{
"id": "CVE-2021-35394",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2021-35394",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "active"
},
{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2025-02-04T19:37:46.125761Z"
}
}
],
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 10,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:L/Au:N/C:C/I:C/A:C",
"authentication": "NONE",
"integrityImpact": "COMPLETE",
"accessComplexity": "LOW",
"availabilityImpact": "COMPLETE",
"confidentialityImpact": "COMPLETE"
},
"acInsufInfo": false,
"impactScore": 10,
"baseSeverity": "HIGH",
"obtainAllPrivilege": false,
"exploitabilityScore": 10,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 9.8,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 3.9
},
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 9.8,
"attackVector": "NETWORK",
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "cve@mitre.org",
"affectedData": [
{
"vendor": "n/a",
"product": "n/a",
"versions": [
{
"status": "affected",
"version": "n/a"
}
]
}
]
}
],
"published": "2021-08-16T12:15:07.267",
"references": [
{
"url": "https://www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain",
"tags": [
"Broken Link",
"Exploit",
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://www.realtek.com/en/cu-1-en/cu-1-taiwan-en",
"tags": [
"Broken Link",
"Patch",
"Vendor Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2021-35392_35395.pdf",
"tags": [
"Patch",
"Vendor Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://www.securityfocus.com/archive/1/534765",
"tags": [
"Broken Link",
"Third Party Advisory",
"VDB Entry"
],
"source": "cve@mitre.org"
},
{
"url": "https://www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain",
"tags": [
"Broken Link",
"Exploit",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.realtek.com/en/cu-1-en/cu-1-taiwan-en",
"tags": [
"Broken Link",
"Patch",
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2021-35392_35395.pdf",
"tags": [
"Patch",
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.securityfocus.com/archive/1/534765",
"tags": [
"Broken Link",
"Third Party Advisory",
"VDB Entry"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-35394",
"tags": [
"US Government Resource"
],
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "NVD-CWE-Other"
}
]
},
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"description": [
{
"lang": "en",
"value": "CWE-78"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Realtek Jungle SDK version v2.x up to v3.4.14B provides a diagnostic tool called 'MP Daemon' that is usually compiled as 'UDPServer' binary. The binary is affected by multiple memory corruption vulnerabilities and an arbitrary command injection vulnerability that can be exploited by remote unauthenticated attackers."
},
{
"lang": "es",
"value": "SDK de Realtek Jungle versiones v2.x hasta v3.4.14B, proporciona una herramienta de diagnóstico llamada \"MP Daemon\" que normalmente es compilado como binario \"UDPServer\". El binario está afectado por múltiples vulnerabilidades de corrupción de memoria y una vulnerabilidad de inyección de comandos arbitrarios que puede ser explotada por atacantes no autenticados remotos."
}
],
"lastModified": "2026-06-17T03:57:29.187",
"cisaActionDue": "2021-12-24",
"cisaExploitAdd": "2021-12-10",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:realtek:rtl819x_jungle_software_development_kit:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "00E83926-7610-44FA-9837-B03D386A07D5",
"versionEndIncluding": "3.4.14b",
"versionStartIncluding": "2.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "cve@mitre.org",
"cisaRequiredAction": "Apply updates per vendor instructions.",
"cisaVulnerabilityName": "Realtek Jungle SDK Remote Code Execution Vulnerability"
}