yhy0 Access Control Penetration Testing Patterns
当对 Web 应用进行访问控制和权限提升渗透测试时加载此 Skill。覆盖垂直/水平越权、多租户隔离绕过等。
与其他 Skill 的关系：本 Skill 聚焦授权层面的访问控制（谁能访问什么资源）。对象级授权（IDOR）详见
pentest-idor，认证绕过（登录/OTP/2FA）详见pentest-auth-bypass。
Attack Surface Discovery
高风险功能区域：
- 管理后台：
/admin、/dashboard、/management路径 - 用户角色管理：角色分配、权限修改接口
- 多租户系统：组织/团队切换、跨租户数据访问
- SSO/SAML/OAuth 集成：认证断言处理、签名验证
- 密码重置/账户恢复流程
- API 端点：缺少认证中间件的端点
- OTP/验证码机制：验证逻辑、速率限制
识别信号：
- 前端隐藏但后端存在的管理接口（JS 代码中的路由定义）
- 不同角色响应内容的差异（管理员看到更多字段）
- API 文档中标注 "admin only" 但实际未校验的端点
- 测试环境/调试端点遗留在生产环境
Exploitation Techniques
垂直权限提升（User → Admin）：
# 直接访问管理路径
GET /admin/users
GET /api/admin/settings
# 修改角色参数
POST /api/users/me {"role": "admin"}
PUT /api/users/me {"is_admin": true}
# 利用参数污染
POST /register {"username": "test", "role": "user", "role": "admin"}
# HTTP 头绕过
X-Original-URL: /admin/users
X-Rewrite-URL: /admin/users
API Gateway / 中间件绕过：
- 路径规范化差异：
/admin/./users、/ADMIN/users、/admin%2fusers - HTTP 方法覆盖：
X-HTTP-Method-Override: PUT、_method=DELETE - IP 白名单绕过：
X-Forwarded-For: 127.0.0.1、X-Real-IP: 127.0.0.1 - 路径参数注入：
/api/v1/users;admin=true/profile（Tomcat/Spring）
RBAC 测试矩阵：
- 枚举所有角色（admin、manager、user、guest）和所有端点
- 构建 Role × Endpoint 矩阵，用每个角色的凭证测试每个端点
- 关注：高权限端点（CRUD 用户、系统配置）是否对低权限角色返回 403
水平权限提升（User A → User B）：
# 修改请求中的用户标识
GET /api/users/1001/profile → GET /api/users/1002/profile
POST /api/account {"user_id": "victim_id"}
# 密码重置流程账户切换
POST /api/reset-password {"token": "valid_token", "email": "victim@target.com"}
- 通过 OTP 泄露接管他人账户
多租户隔离绕过：
- 修改
tenant_id/org_id参数访问其他租户数据 - GraphQL 查询中跨租户查询
- 共享资源（文件存储、缓存）中的租户数据泄露
SSO/SAML 攻击：
- SAML 签名验证绕过：修改断言中的用户身份但签名仍有效
- XML 签名包装攻击
- OAuth redirect_uri 篡改
- JWT 算法混淆（
alg: none、RS256 → HS256）
认证流程利用：
- 密码重置 token 重用或可预测
- OTP 在 API 响应中泄露
- 验证码绕过（修改响应、速率限制绕过、验证码重用）
- 账户恢复流程中的身份验证缺失
Detection Checklist
- 枚举所有 API 端点并测试未认证访问
- 对每个管理功能用普通用户凭证测试是否可访问
- 测试角色参数是否可被客户端篡改（注册、更新 profile）
- 验证多租户隔离（切换 tenant_id 是否可访问其他租户数据）
- 检查 SAML/OAuth/JWT 实现的安全性（签名验证、算法限制）
- 测试密码重置流程（token 可预测性、跨账户使用）
- 检查 OTP/验证码是否在 API 响应中泄露
- 测试速率限制是否可绕过（更换 IP、修改参数）
- 检查前端路由中隐藏的管理页面
- 验证 API 端点的 HTTP 方法限制是否完整
Impact Assessment
漏洞利用可达到的效果：
- 完整账户接管：通过密码重置、OTP 泄露等接管任意账户
- 管理权限获取：普通用户提升为管理员
- 跨租户数据泄露：访问其他组织的敏感数据
- 系统完全控制：利用管理权限修改系统配置、访问所有数据
- 大规模数据泄露：利用未授权端点批量提取用户 PII
严重度判断：
- Critical：可接管任意账户、SAML 签名绕过登录任意用户、可获取管理权限
- High：跨租户数据访问、OTP 泄露导致可接管特定账户
- Medium：仅可访问低敏感度的管理信息、需要额外条件链式利用
Real-World Cases
以下案例来自 HackerOne 公开披露的真实漏洞报告，展示了该类漏洞在实际目标中的表现形式。
Case 1: Cosmos — Unauthorized coins transfer from locking account(s)
- 严重度: Critical | CWE: Improper Access Control - Generic
- 摘要: The Cosmos SDK was found to have a vulnerability that allowed unauthorized transfer of funds from locking accounts. The issue was specifically identified in the
periodic-locking-account, but it was ... - 报告: https://hackerone.com/reports/2976481
Case 2: Enjin — Lack of Tenant Scoping Enables Limited Cross-Tenant Data Querying and Mutation
- 严重度: Critical | CWE: Improper Access Control - Generic
- 摘要: A vulnerability was demonstrated on the Enjin Platform that allowed for limited cross-tenant data querying and mutation, enabling querying or mutating of someone else's data in certain cases. A full a...
- 报告: https://hackerone.com/reports/2327238
Case 3: GitHub — SAML Signature verification bypass allows logging into any user (with specific conditions)
- 严重度: Critical | CWE: Improper Access Control - Generic
- 摘要: The vulnerability allowed an attacker with direct network access to GitHub Enterprise Server to forge a SAML response and gain unauthorized access to the instance, including site administrator privile...
- 报告: https://hackerone.com/reports/2579939
Case 4: GitLab — Account Takeover via Password Reset without user interactions
- 严重度: Critical | CWE: Improper Access Control - Generic
- 摘要: The report submitted to GitLab described a vulnerability that allowed account takeover via the password reset form. The vulnerability was triggered by modifying the JSON request to include the victim'...
- 报告: https://hackerone.com/reports/2293343
Case 5: IBM — Unauthenticated Remote Access to Testing Endpoint
- 严重度: Critical | CWE: Improper Access Control - Generic
- 摘要: Unauthenticated remote access to a testing endpoint was reported, analyzed and remediated.
- 报告: https://hackerone.com/reports/2192984
Case 6: MTN Group — Admin Dashboard Access Leads to Updating Merchant Info
- 严重度: Critical | CWE: Improper Access Control - Generic
- 摘要: The application had a hidden registration endpoint that allowed an unauthorized user to sign up for an admin portal. This granted the user access to the admin dashboard, where they could view, edit, a...
- 报告: https://hackerone.com/reports/2801787
Case 7: MTN Group — Unauthorized access to PII leads to Administrator account Takeover
- 严重度: Critical | CWE: Privilege Escalation
- 摘要: The vulnerability arises from insufficient restrictions placed on the list of post authors, which could be exploited by remote attackers to obtain sensitive information through wp/v2/users/15 requests...
- 报告: https://hackerone.com/reports/2450685
Case 8: MTN Group — OTP code Leaked in API Response
- 严重度: Critical | CWE: Improper Access Control - Generic
- 摘要: The application allowed users to sign up for device insurance. When getting a quote, an OTP code was sent to the user's phone number for authentication, but the same OTP code was also returned in the ...
- 报告: https://hackerone.com/reports/2633888
Case 9: Mars — unauthorized access and add user and change personal information all users
- 严重度: Critical | CWE: Improper Access Control - Generic
- 摘要: The report describes a vulnerability in the ██████████ website, where unauthorized access to an API endpoint allowed attackers to add new users and modify personal information of existing users. The v...
- 报告: https://hackerone.com/reports/2828641
Case 10: Mars — change part of personal information all users
- 严重度: Critical | CWE: Improper Access Control - Generic
- 摘要: The report describes a vulnerability in the ██████████ website, where unauthorized access to an API endpoint allowed attackers to add new users and modify personal information of existing users. The v...
- 报告: https://hackerone.com/reports/2828693