What’s Vulnerable › Vulnerabilities

CVE-2021-36213

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-07-17 · updated 2026-06-17

Description

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.

Affected products

• HashiCorp Consul: from 1.9.0 before 1.9.8; from 1.10.0 before 1.10.1 — fixed in 1.10.1, 1.9.8

How to fix

Upgrade to a fixed version: HashiCorp Consul 1.10.1, 1.9.8. Check the vendor advisory for mitigations.

References

• https://discuss.hashicorp.com/t/hcsec-2021-16-consul-s-application-aware-intentions-deny-action-fails-open-when-combined-with-default-deny-policy/26855
• https://github.com/hashicorp/consul/releases/tag/v1.10.1
• https://security.gentoo.org/glsa/202208-09
• https://www.hashicorp.com/blog/category/consul
• https://discuss.hashicorp.com/t/hcsec-2021-16-consul-s-application-aware-intentions-deny-action-fails-open-when-combined-with-default-deny-policy/26855
• https://github.com/hashicorp/consul/releases/tag/v1.10.1
• https://security.gentoo.org/glsa/202208-09
• https://www.hashicorp.com/blog/category/consul

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