{
  "crds_version": "0.1",
  "kind": "base",
  "id": "crds:cve-2021-35394",
  "revision": 1,
  "title": "Realtek Jungle SDK — Command Execution in the Diagnostic Daemon",
  "summary": "A diagnostic daemon in a widely reused Realtek development kit accepts crafted datagrams and runs commands from them, and that kit ships inside routers from many vendors.",
  "source_type": "cve",
  "severity": "critical",
  "cvss": {
    "score": 9.8,
    "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
    "version": "3.1"
  },
  "epss": 0.99861,
  "exploitation": {
    "known_exploited": true,
    "exploit_available": true,
    "attack_complexity": "low",
    "kev_added": "2021-12-10",
    "prerequisites": "Network access to the diagnostic port"
  },
  "remediation": {
    "patch_available": true
  },
  "mitre_attack": [
    "T1190",
    "T1059"
  ],
  "kill_chain": "initial_access",
  "recommended_action": "Apply the device vendor's firmware update, and keep the diagnostic port off every untrusted network.",
  "confidence": "high",
  "provenance": [
    {
      "fields": [
        "cvss",
        "exploitation.attack_complexity",
        "exploitation.exploit_available",
        "references",
        "published_at"
      ],
      "source": "https://nvd.nist.gov/vuln/detail/CVE-2021-35394",
      "retrieved_at": "2026-08-07T16:57:17.024Z",
      "confidence": "high",
      "extractor": "scrty-crds-pipeline/0.1"
    },
    {
      "fields": [
        "exploitation.known_exploited",
        "exploitation.kev_added"
      ],
      "source": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "retrieved_at": "2026-08-07T16:57:17.024Z",
      "confidence": "high",
      "extractor": "scrty-crds-pipeline/0.1"
    },
    {
      "fields": [
        "epss"
      ],
      "source": "https://api.first.org/data/v1/epss?cve=CVE-2021-35394",
      "retrieved_at": "2026-08-07T16:57:17.024Z",
      "confidence": "high",
      "extractor": "scrty-crds-pipeline/0.1"
    },
    {
      "fields": [
        "title",
        "summary",
        "severity",
        "remediation",
        "mitre_attack",
        "kill_chain",
        "recommended_action",
        "confidence",
        "tags",
        "exploitation.prerequisites"
      ],
      "source": "https://nvd.nist.gov/vuln/detail/CVE-2021-35394",
      "retrieved_at": "2026-08-07T16:57:17.024Z",
      "confidence": "high",
      "extractor": "claude-code"
    }
  ],
  "references": [
    {
      "type": "cve",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-35394",
      "label": "NVD record"
    },
    {
      "type": "cisa",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "label": "CISA Known Exploited Vulnerabilities catalog"
    },
    {
      "type": "vendor_advisory",
      "url": "https://www.realtek.com/en/cu-1-en/cu-1-taiwan-en"
    },
    {
      "type": "vendor_advisory",
      "url": "https://www.realtek.com/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2021-35392_35395.pdf"
    },
    {
      "type": "exploit",
      "url": "https://www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain"
    }
  ],
  "published_at": "2021-08-16T12:15:07.267Z",
  "issued_at": "2026-08-07T16:57:17.024Z",
  "tags": [
    "realtek",
    "router",
    "iot",
    "command-injection"
  ]
}