Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Endpoint is explicitly public with no auth middleware; impact is confined to low-integrity metric inflation with no confidentiality or availability loss.
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Lifecycle Timeline
3DescriptionCVE.org
Ech0 before 4.7.3 contains an authentication bypass vulnerability in the PUT /api/echo/like/:id endpoint that allows unauthenticated attackers to increment engagement metrics without identity verification or rate limiting. Attackers can send repeated requests to arbitrarily inflate the fav_count field for any known echo identifier, compromising the integrity of engagement metrics and social ranking systems.
AnalysisAI
Unauthenticated metric inflation in Ech0 before 4.7.3 allows any remote attacker to arbitrarily increment the fav_count field of any post by repeatedly calling PUT /api/echo/like/:id without credentials or rate limiting. The endpoint is explicitly registered on the public router group, bypassing all JWT authentication middleware, and the service layer performs no identity check or per-user binding before executing the database increment. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | No authentication is required - the route is registered in PublicRouterGroup, which explicitly excludes JWT middleware enforcement. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 4.0 score of 6.9 accurately reflects the attack profile: network-accessible (AV:N), no complexity barrier (AC:L), no authentication required (PR:N), no user interaction (UI:N), with low integrity impact (VI:L) and no confidentiality or availability consequence. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker finds a publicly reachable Ech0 instance and issues a single unauthenticated GET /api/echo/page request to enumerate valid echo UUIDs from the public timeline. They then script a loop of unauthenticated PUT /api/echo/like/{ECHO_ID} requests - exactly as demonstrated in the GHSA proof-of-concept - inflating the fav_count of a targeted post by an arbitrary amount to manipulate its ranking in feeds or search results. |
| Remediation | Upgrade Ech0 to version 4.7.3 or later, which incorporates the fix from commit a7e8b8e84bd1e3db090dfb720f2c6c433356b442; Go module consumers should update to github.com/lin-snow/ech0 at pseudo-version 1.4.8-0.20260503040728-a7e8b8e84bd1 or any later tagged release. … Detailed patch versions, workarounds, and compensating controls in full report. |
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Same technique Authentication Bypass
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-65446
GHSA-7v7f-8gw6-2q2x