Vulnerability in HashiCorp Consul (CVE-2021-36213)

Summary

Vulnerability in HashiCorp Consul (CVE-2021-36213). Data can be tampered with by attackers. Mitigation: upgrade to 1.9.8 or later.

Original description

The description as published by the source.

HashiCorp Consul and Consul Enterprise 1.9.0 through 1.10.0 default deny policy with a single L7 application-aware intention deny action cancels out, causing the intention to incorrectly fail open, allowing L4 traffic. Fixed in 1.9.8 and 1.10.1.

Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2021-36213 has been found in HashiCorp Consul.
Data can be tampered with by attackers.
What to do: upgrade HashiCorp Consul to 1.9.8 or later.
If unsure, ask your IT team or search "HashiCorp Consul CVE-2021-36213" on the vendor's site.

CVE-2021-36213 (HashiCorp Consul)
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 1.9.8 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in HashiCorp Consul.

📍 Affected scope

Check the vendor advisory for the affected versions of HashiCorp Consul.

🔥 Severity

Severity: ?. Data can be tampered with by attackers.

🔧 How to fix

Update to 1.9.8.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
資産台帳・SBOM・依存マニフェストで HashiCorp Consul を使っているサービスとバージョンを洗い出す。
2
Apply patch patch
```
Upgrade HashiCorp Consul to 1.9.8
```
ステージング環境で 1.9.8 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

References

advisory discuss.hashicorp.com
advisory github.com
advisory security.gentoo.org
advisory hashicorp.com