CVE-2018-19653
MEDIUMCVE-2018-19653 is a medium-severity (CVSS 5.9) CWE-310 vulnerability in github.com/hashicorp/consul. O3 Security confirms whether CVE-2018-19653 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
HashiCorp Consul can use cleartext agent-to-agent RPC communication
Blast Radius
github.com/hashicorp/consulReal-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
HashiCorp Consul 0.5.1 through 1.4.0 can use cleartext agent-to-agent RPC communication because the verify_outgoing setting is improperly documented. NOTE: the vendor has provided reconfiguration steps that do not require a software upgrade.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/hashicorp/consul | ≥ 0.5.1&&< 1.4.1 | 1.4.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/hashicorp/consul. 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 github.com/hashicorp/consul to 1.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-19653 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 CVE-2018-19653 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 CVE-2018-19653. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2018-19653 in your dependencies?
O3 detects CVE-2018-19653 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.