Squid Proxy - HTTP Authentication Credentials Disclosure

id: CVE-2025-62168

info:
  name: Squid Proxy - HTTP Authentication Credentials Disclosure
  author: xtr0nix
  severity: critical
  description: |
    Squid versions prior to 7.2 fail to redact HTTP authentication credentials in error page responses. The Authorization header value is embedded in plain text inside the mailto: diagnostic block when Squid generates an error page (e.g. ERR_DNS_FAIL).
  impact: |
    Attackers can extract tokens and credentials used by trusted clients or backend applications proxied through Squid.
  remediation: |
    Update to the version 7.2+ or disable debug information in administrator mailto links generated by Squid by configuring squid.conf with email_err_data off.
  reference:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-62168
    - https://github.com/squid-cache/squid/security/advisories/GHSA-c8cc-phh7-xmxr
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 10.0
    cve-id: CVE-2025-62168
    epss-score: 0.6332
    epss-percentile: 0.99108
    cwe-id: CWE-209
  metadata:
    verified: true
    max-request: 1
  tags: cve,cve2025,info-disclosure,squid,proxy

variables:
  token: "{{randstr}}"
  invalid_host: "{{rand_base(16)}}.invalid"

http:
  - raw:
      - |+
        GET http://{{invalid_host}}/ HTTP/1.1
        Host: {{invalid_host}}
        Authorization: Bearer {{token}}

    unsafe: true

    matchers:
      - type: dsl
        dsl:
          - 'status_code == 503'
          - 'contains(body, "mailto:")'
          - 'contains(body, "ERR_DNS_FAIL")'
          - 'contains(body, "{{token}}")'
        condition: and

    extractors:
      - type: regex
        part: body
        name: leaked-token
        regex:
          - "Authorization%3A%20Bearer%20([^%]+)"
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