CVE-2021-20021: SonicWall Email Security <= 10.0.9.x - Unauthenticated Admin Account Creation

2025-08-01 SonicWall Email Security PoC Public

Description

SonicWall Email Security version 10.0.9.x allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host.

PoC

id: CVE-2021-20021

info:
  name: SonicWall Email Security <= 10.0.9.x - Unauthenticated Admin Account Creation
  author: pussycat0x
  severity: critical
  description: |
    SonicWall Email Security version 10.0.9.x allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host.
  impact: |
    Attackers can create admin accounts remotely, leading to full control over the email security system.
  remediation: |
    Update to the latest version of SonicWall Email Security or apply security patches provided by SonicWall.
  reference:
    - https://www.sonicwall.com/support/product-notification/security-notice-sonicwall-email-security-zero-day-vulnerabilities/210416112932360
    - https://nvd.nist.gov/vuln/detail/CVE-2021-20021
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2021-20021
    cwe-id: CWE-269
    epss-score: 0.83425
    epss-percentile: 0.99665
    cpe: cpe:2.3:a:sonicwall:email_security:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    shodan-query: product:"SonicWALL Email Security"
    vendor: sonicwall
    product: email_security
  tags: cve,cve2021,sonicwall,email-security,auth-bypass,kev,passive,vkev,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/login.html"

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 200'
          - 'compare_versions(version, " <= 10.0.9")'
          - 'contains(body, "logonTitle\">Email Security Login")'
          - 'contains(header, "Apache-Coyote/1.1")'
        condition: and

    extractors:
      - type: regex
        part: body
        group: 1
        name: version
        regex:
          - 'class="lefthand">([0-9.]+)'
# digest: 4a0a00473045022069da284f97fda6510754bcd7f6e54651b52405dca3b84c1185addfddc7309f52022100e51c0f1892ba106d02fc62e3b7dcad237138cc99ba93227080670ece5a4ebc5a:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.

References

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