CVE-2026-79671

Ech0 before 4.4.3 fails to enforce scope-based authorization on nine comment panel admin endpoints, allowing access tokens with minimal scopes to perform full comment moderation operations. Attackers with a limited-scope access token can list, approve, reject, delete comments, and modify comment system settings by directly accessing the unprotected panel endpoints.

Ech0 before 4.4.3 lacks authorization checks on system log endpoints allowing any authenticated non-admin user to read and stream all server logs. Attackers can access historical logs and real-time log streams via GET /api/system/logs, GET /api/system/logs/stream, and WS /ws/system/logs to gather reconnaissance data including internal file paths, error stack traces, and application state.

Ech0 version 4.3.4 and earlier fails to reliably enforce scoped access token (least-privilege) restrictions on several privileged admin routes. Multiple privileged endpoints (e.g., /api/inbox, /api/panel/comments, /api/backup/export) omit scope checks and authorize based only on the user's admin role, and the backup export handler discards token scope metadata entirely. An attacker holding a deliberately limited (low-scope) admin access token can reach broader privileged functionality than intended, including reading the inbox and exporting a full database backup ZIP archive. Fixed in 4.4.3.

Ech0 before 4.5.1 contains an authorization bypass vulnerability where session tokens skip scope validation in RequireScopes middleware, allowing logged-in non-admin users to access admin endpoints. Attackers can read system logs, visitor statistics, user emails, and subscribe to live WebSocket logs by sending authenticated session tokens to unprotected endpoints.

Ech0 before 4.7.3 fails to properly revoke access tokens created with never-expire option, allowing attackers to maintain perpetual authenticated access after token theft. Three independent revocation mechanisms fail: logout panics on nil ExpiresAt field, RevokeToken skips when remainTTL is zero, and admin delete does not blacklist the JTI, leaving stolen tokens cryptographically valid until JWT secret rotation.

Ech0 through 4.5.6 contains an OAuth redirect URI validation vulnerability in parseAndValidateClientRedirect (internal/service/auth/auth.go) that compares only the scheme and host of the client-supplied redirect_uri against the admin-configured allowlist, ignoring path, query, and fragment components. The redirect_uri is embedded into the signed state JWT at login time without validation. An attacker can craft a redirect_uri whose host matches an allowed origin but whose path is attacker-influenced; after the OAuth exchange the victim is redirected to that path with a one-time exchange code in the query string. If the code leaks (e.g., via Referer, analytics, or an open redirect on that host), the attacker can trade it at the public POST /api/auth/exchange endpoint for the victim's access and refresh tokens. Fixed in 4.7.3.

Ech0 versions before 4.7.3 expose guest commenter email addresses through public API endpoints due to improper JSON serialization tags on the Comment model. Unauthenticated attackers can harvest all commenter emails by calling the /api/comments and /api/comments/public endpoints without authentication.

Ech0 before 4.7.3 contains a server-side request forgery vulnerability in the fetchPeerConnectInfo function that uses unvalidated HTTP requests instead of safe request methods with URL validation. Authenticated attackers can supply arbitrary URLs to access internal services and cloud metadata endpoints by triggering connection health checks or peer connection operations.

Ech0 before 4.4.3 protects the PUT /user endpoint with the profile:read scope, a read-only scope, but allows write operations including password changes. An attacker with an admin's profile:read access token can change the admin's password and login to obtain an unrestricted session token that bypasses all scope enforcement.

Ech0 before 4.4.3 contains a stored cross-site scripting vulnerability in the file upload endpoint that validates Content-Type using only client-supplied headers without server-side inspection. Attackers with admin privileges can upload SVG or HTML files containing JavaScript that executes in the application origin when accessed by any user, enabling session hijacking and data exfiltration.