GHSA-6vch-q96h-7gc3
etcd: `tlsListener.acceptLoop` spawns unbounded handshake goroutines with no deadline
Blast Radius
go.etcd.io/etcd/v3🐹go.etcd.io/etcd/v3🐹go.etcd.io/etcd/v3Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Impact
What kind of vulnerability is it? Who is impacted?
A network attacker who can reach an etcd TLS listener can open many TCP connections and never send a ClientHello. Each connection spawns a goroutine in the etcd server process that blocks indefinitely inside tls.Conn.Handshake(), and each is tracked in the pending map. Unbounded goroutine and map growth exhausts memory in the etcd process, causing loss of availability for the etcd cluster (and, when etcd backs Kubernetes, the control plane).
Patches
Has the problem been patched? What versions should users upgrade to?
This vulnerability is patched in the following versions:
- etcd 3.7.1
- etcd 3.6.14
- etcd 3.5.33
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
If upgrading is not immediately possible, then restrict network access. Limit which hosts can reach etcd's client (gRPC) port via firewall rules or network policy, reducing who can attempt exploitation.
Reporter
VMware By Broadcom
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | go.etcd.io/etcd/v3 | ≥ 3.7.0-alpha.0&&< 3.7.1 | 3.7.1 |
| 🐹Go | go.etcd.io/etcd/v3 | ≥ 3.6.0&&< 3.6.14 | 3.6.14 |
| 🐹Go | go.etcd.io/etcd/v3 | all versions | 3.5.33 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for go.etcd.io/etcd/v3. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update go.etcd.io/etcd/v3 to 3.7.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6vch-q96h-7gc3 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-6vch-q96h-7gc3 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-6vch-q96h-7gc3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-6vch-q96h-7gc3 in your dependencies?
O3 detects GHSA-6vch-q96h-7gc3 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.