Ech0 allows PUT /api/echo/like/:id unauthenticated: anonymous callers to modify any echo's fav_count

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary PUT /api/echo/like/:id at internal/router/echo.go:12 is registered on PublicRouterGroup with no authentication and no rate limit. Anonymous callers increment the favcount counter on any echo (including private echoes) by UUID, repeat the request without deduplication, and trigger a database write plus a four-key cache invalidation on every call. Alice harvests echo UUIDs from the public GET /api/echo/page response, inflates fav counts at will, and spams writes to amplify load on the DB and cache layers. Details Route registration at internal/router/echo.go:12: PublicRouterGroup is r.Group("/api") without the JWT middleware that AuthRouterGroup applies. The handler passes through to EchoService.LikeEcho, which calls EchoRepository.LikeEcho at internal/repository/echo/echo.go:270: No viewer check, no ownership check, no private-flag check. Compare the read path at EchoService.GetEchoById (internal/service/echo/echo.go:275-300) which rejects anonymous readers on private echoes;…

Published by the source

7 May 2026, 21:23 UTC

Last modified by the source

7 May 2026, 21:23 UTC

Source last checked

26 Oct 2026, 15:20 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-pj6q-4vq4-r8cg

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: GHSA-pj6q-4vq4-r8cg

Advisory: Ech0 allows PUT /api/echo/like/:id unauthenticated: anonymous callers to modify any echo's fav_count
IDs: GHSA-pj6q-4vq4-r8cg
Record: https://patchnext.com/advisories/ghsa-pj6q-4vq4-r8cg (revision 1, source checked 26 Oct 2026, 15:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/lin-snow/Ech0 1.4.8-0.20260503035905-cecc2c19b590. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/lin-snow/Ech0: affected < 1.4.8-0.20260503035905-cecc2c19b590; fixed in 1.4.8-0.20260503035905-cecc2c19b590

## Suggested inspection (read-only)
- Go github.com/lin-snow/Ech0: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/lin-snow/Ech0.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-pj6q-4vq4-r8cg (GitHub-reviewed advisory GHSA-pj6q-4vq4-r8cg lists affected ranges: Go github.com/lin-snow/Ech0 >=0 <1.4.8-0.20260503035905-cecc2c19b590)

Commands are suggestions: review each one before running it.