Ech0 has Server-Side Request Forgery (SSRF) via Connect Handler fetchPeerConnectInfo

Exploitation

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

CVSS

7.7 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Summary The fetchPeerConnectInfo function in internal/service/connect/connect.go:214-239 uses httpUtil.SendRequest (no SSRF protection) instead of SendSafeRequest (which has ValidatePublicHTTPURL with private IP blocking). This allows authenticated users to make the server request arbitrary URLs including internal/cloud metadata endpoints. Details In internal/service/connect/connect.go, the fetchPeerConnectInfo function: This uses SendRequest which has NO URL validation. The codebase HAS SendSafeRequest at internal/util/http/http.go:228-281 with proper SSRF protection, but fetchPeerConnectInfo does not use it. Called from: - Line 307: data, err := fetchPeerConnectInfo(conn.ConnectURL, requestTimeout) - - Line 498: data, err := fetchPeerConnectInfo(conn.ConnectURL, healthProbeTimeout) PoC Or for Kubernetes: Impact - Confidentiality: SSRF can access internal services, cloud metadata (AWS IMDSv1, GCE metadata), Kubernetes API - - CWE-918: Server-Side Request Forgery

Published by the source

7 May 2026, 21:28 UTC

Last modified by the source

7 May 2026, 21:28 UTC

Source last checked

26 Oct 2026, 15:20 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8mc6-xjpr-h98x

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

# Patch Next advisory brief: GHSA-8mc6-xjpr-h98x

Advisory: Ech0 has Server-Side Request Forgery (SSRF) via Connect Handler fetchPeerConnectInfo
IDs: GHSA-8mc6-xjpr-h98x
Record: https://patchnext.com/advisories/ghsa-8mc6-xjpr-h98x (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: High (CVSS 7.7)
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 1.4.8-0.20260503040602-091d26d2d942. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/lin-snow/ech0: affected < 1.4.8-0.20260503040602-091d26d2d942; fixed in 1.4.8-0.20260503040602-091d26d2d942

## 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-8mc6-xjpr-h98x (GitHub-reviewed advisory GHSA-8mc6-xjpr-h98x lists affected ranges: Go github.com/lin-snow/ech0 >=0 <1.4.8-0.20260503040602-091d26d2d942)

Commands are suggestions: review each one before running it.