Advisories for Golang/Github.com/Lin-Snow/Ech0 package

2026

Ech0's Missing Authorization on System Logs Allows Non-Admin Information Disclosure

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.

Ech0 Scope Bypass: profile:read Access Token Can Change Admin Password and Escalate to Unrestricted Session

The PUT /user endpoint is protected by RequireScopes("profile:read"), which is a read-only scope. However, the endpoint performs write operations including password changes. An attacker who obtains an admin's restricted profile:read access token can change the admin's password, then login to receive an unrestricted session token that bypasses all scope enforcement.

Ech0 has Stored XSS via SVG Upload and Content-Type Validation Bypass in File Upload

The file upload endpoint validates Content-Type using only the client-supplied multipart header, with no server-side content inspection or file extension validation. Combined with an unauthenticated static file server that determines Content-Type from file extension, this allows an admin to upload HTML/SVG files containing JavaScript that execute in the application's origin when visited by any user. Additionally, image/svg+xml is in the default allowed types, enabling stored XSS via SVG without any …

Ech0 has SSRF via DNS Resolution Bypass in Webhook URL Validation

The validateWebhookURL function in webhook_setting_service.go attempts to block webhooks targeting private/internal IP addresses, but only checks literal IP strings via net.ParseIP(). Hostnames that DNS-resolve to private IPs (e.g., 169.254.169.254.nip.io, 10.0.0.1.nip.io) bypass all checks, allowing an admin to create webhooks that make server-side requests to internal network services and cloud metadata endpoints.

Ech0 Comment Panel Endpoints Missing RequireScopes Middleware — Scoped Access Token Bypass

All 9 comment panel admin endpoints (/api/panel/comments/*) are missing RequireScopes() middleware, while every other admin endpoint in the application enforces scope-based authorization on access tokens. An admin-issued access token scoped to minimal permissions (e.g., echo:read only) can perform full comment moderation operations including listing, approving, rejecting, deleting comments, and modifying comment system settings.

Ech0: Unauthenticated SSRF in GetWebsiteTitle allows access to internal services and cloud metadata

The GET /api/website/title endpoint accepts an arbitrary URL via the website_url query parameter and makes a server-side HTTP request to it without any validation of the target host or IP address. The endpoint requires no authentication. An attacker can use this to reach internal network services, cloud metadata endpoints (169.254.169.254), and localhost-bound services, with partial response data exfiltrated via the HTML <title> tag extraction.

Ech0 has Unauthenticated Server-Side Request Forgery in Website Preview Feature

Ech0 implements link preview (editor fetches a page title) through GET /api/website/title. That is legitimate product behavior, but the implementation is unsafe: the route is unauthenticated, accepts a fully attacker-controlled URL, performs a server-side GET, reads the entire response body into memory (io.ReadAll). There is no host allowlist, no SSRF filter, and InsecureSkipVerify: true on the outbound client. Attacker outcome : Anyone who can reach the instance can force the …