Executive brief
Ech0 is a social media feed application. An unprotected endpoint allows anyone on the network to artificially boost the popularity counter of any post without authentication or rate limits. Attackers can damage platform integrity by manipulating trending rankings and overwhelming the database with repeated write requests.
Technical details
The PUT /api/echo/like/:id endpoint is registered on the public router group without JWT authentication or rate limiting. The vulnerable LikeEcho handler in internal/repository/echo/echo.go:270 performs no visibility checks and accepts repeated increment requests from the same IP without deduplication. Attackers can harvest post UUIDs from the public GET /api/echo/page feed or via other channels (logs, referer headers, shared drafts) and craft repeated PUT requests to inflate fav_count on any echo, including private echoes. Each request triggers a database UPDATE transaction plus four cache key invalidations, amplifying load on storage and caching layers. The issue is fixed in version 4.7.3 by moving the route to AuthRouterGroup, adding per-user deduplication, and implementing rate limiting middleware.
Affected products
- lin-snow Ech0 through 4.5.6
Timeline
- 2026-05-03: disclosed: GitHub Security Advisory published
- 2026-04: patched: Fixed in version 4.7.3
- 2026-08-25: advisory: CVE-2026-79661 published on NVD