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Ech0's Missing Authorization on System Logs Allows Non-Admin Information Disclosure — github.com/lin-snow/ech0

Missing Authorization

Summary

The system log endpoints (GET /api/system/logs, GET /api/system/logs/stream, WS /ws/system/logs) lack authorization checks, allowing any authenticated non-admin user to read and stream all server logs. These logs contain error stack traces, internal file paths, module names, and arbitrary structured fields that facilitate reconnaissance for further attacks.

Details

The dashboard routes in internal/router/dashboard.go:7-8 register log endpoints on the AuthRouterGroup without any RequireScopes middleware:

// internal/router/dashboard.go func setupDashboardRoutes(appRouterGroup *AppRouterGroup, h *handler.Bundle) { appRouterGroup.AuthRouterGroup.GET("/system/logs", h.DashboardHandler.GetSystemLogs()) appRouterGroup.AuthRouterGroup.GET("/system/logs/stream", h.DashboardHandler.SSESubscribeSystemLogs()) appRouterGroup.WSRouterGroup.GET("/system/logs", h.DashboardHandler.WSSubscribeSystemLogs()) }

Compare with other admin-only routes that properly use RequireScopes:

// internal/router/setting.go — every route has RequireScopes appRouterGroup.AuthRouterGroup.GET("/settings", middleware.RequireScopes(authModel.ScopeAdminSettings), h.SettingHandler.GetSiteSettings())

The AuthRouterGroup only applies JWTAuthMiddleware() (router.go:36), which validates the JWT and sets the viewer context but does not check admin status. The WSRouterGroup (router.go:37) has no middleware at all — the WebSocket handler only calls ParseToken to verify the JWT signature (dashboard.go:74) without any role/scope validation.

The handler (internal/handler/dashboard/dashboard.go:29-62) and service (internal/service/dashboard/dashboard.go:21-27) contain zero authorization checks. Other services in the codebase properly enforce admin access:

  • internal/service/inbox/inbox.go:132 — ensureAdmin()
  • internal/service/migrator/migrator.go:360 — ensureAdmin()
  • internal/service/comment/comment.go:719 — requireAdmin()

Non-admin users are created with IsAdmin: false and IsOwner: false (internal/service/user/user.go:220-221) via the public registration endpoint.

The LogEntry struct (internal/util/log/log.go:78-87) exposes:

type LogEntry struct { Time string `json:"time"` Level string `json:"level"` Msg string `json:"msg"` Module string `json:"module,omitempty"` Caller string `json:"caller,omitempty"` // internal file paths Error string `json:"error,omitempty"` // error stack traces Fields map[string]any `json:"fields,omitempty"` // arbitrary structured data Raw string `json:"raw,omitempty"` // raw log lines }

PoC

# 1. Register a non-admin user (system allows up to 5 users by default) curl -X POST http://localhost:8080/api/register \ -H 'Content-Type: application/json' \ -d '{"username":"attacker","password":"Password123"}' # 2. Login to get session token TOKEN=$(curl -s -X POST http://localhost:8080/api/login \ -H 'Content-Type: application/json' \ -d '{"username":"attacker","password":"Password123"}' | jq -r '.data.token') # 3. Read system logs — should require admin but doesn't curl http://localhost:8080/api/system/logs \ -H "Authorization: Bearer $TOKEN" # Returns: {"code":1,"data":[{"time":"...","level":"error","msg":"...","module":"...","caller":"internal/service/user/user.go:145","error":"...","fields":{...}},...]} # 4. Subscribe to real-time log stream via SSE curl -N "http://localhost:8080/api/system/logs/stream?token=$TOKEN" # 5. Subscribe via WebSocket (WSRouterGroup has NO middleware) # wscat -c "ws://localhost:8080/ws/system/logs?token=$TOKEN"

Impact

Any registered non-admin user can:

  • Read all historical system logs including error traces that reveal internal code paths, database errors, and application state
  • Stream real-time logs via SSE or WebSocket to monitor all server activity as it happens
  • Gather reconnaissance data — caller fields expose internal file paths and line numbers, error fields expose stack traces and database query failures, module fields map the internal architecture
  • Monitor other users' actions — authentication failures, registration events, and admin operations appear in logs

This information disclosure lowers the bar for chaining further attacks by revealing the application's internal structure, error handling patterns, and operational state.

Add RequireScopes middleware with an admin scope to the dashboard routes:

// internal/router/dashboard.go func setupDashboardRoutes(appRouterGroup *AppRouterGroup, h *handler.Bundle) { appRouterGroup.AuthRouterGroup.GET("/system/logs", middleware.RequireScopes(authModel.ScopeAdminSettings), h.DashboardHandler.GetSystemLogs()) appRouterGroup.AuthRouterGroup.GET("/system/logs/stream", middleware.RequireScopes(authModel.ScopeAdminSettings), h.DashboardHandler.SSESubscribeSystemLogs()) appRouterGroup.WSRouterGroup.GET("/system/logs", middleware.RequireScopes(authModel.ScopeAdminSettings), h.DashboardHandler.WSSubscribeSystemLogs()) }

Additionally, the WebSocket handler should validate admin scope after parsing the token, since the WSRouterGroup lacks middleware:

// internal/handler/dashboard/dashboard.go — WSSubscribeSystemLogs claims, err := jwtUtil.ParseToken(token) if err != nil { ctx.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"msg": "invalid token"}) return } // Add admin check for WebSocket endpoint if claims.TokenType == authModel.TokenTypeAccess && !containsScope(claims.Scopes, authModel.ScopeAdminSettings) { ctx.AbortWithStatusJSON(http.StatusForbidden, gin.H{"msg": "admin access required"}) return }
  • Published: Apr 10, 2026
  • Updated: Apr 11, 2026
  • GHSA: GHSA-w8jj-cwmc-wgq2
  • Severity: Medium
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Low
  • Score: 4.3
  • AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CWEs:

Software From Fixed in
Go icon github.com/lin-snow/ech0 - 4.4.3

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