{
  "id": "CVE-2021-20038",
  "url": "https://spydr.io/cve/CVE-2021-20038",
  "published": "2021-12-08T10:15:07.750Z",
  "modified": "2026-06-17T03:33:11.327Z",
  "score": 9.8,
  "severity": "critical",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "score_source": "NVD",
  "epss": 0.99912,
  "epss_percentile": 0.99967,
  "exploited": true,
  "kev": {
    "added": "2022-01-28",
    "due": "2022-02-11",
    "action": "Apply updates per vendor instructions.",
    "ransomware": "Known",
    "name": "SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability",
    "notes": "https://nvd.nist.gov/vuln/detail/CVE-2021-20038"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "SonicWall"
  ],
  "products": [
    "SonicWall SMA100"
  ],
  "cwes": [
    "CWE-121",
    "CWE-787"
  ],
  "description": "A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi module environment variables allows a remote unauthenticated attacker to potentially execute code as a 'nobody' user in the appliance. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances firmware 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv and earlier versions.",
  "status": "Analyzed",
  "score_type": "Primary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 9.8,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "https://github.com/jbaines-r7/badblood",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026",
      "tags": [
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://www.rapid7.com/blog/post/2022/01/11/cve-2021-20038-42-sonicwall-sma-100-multiple-vulnerabilities-fixed-2/",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20038",
      "tags": [
        "US Government Resource"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2021-20038",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}