7.5
HIGH
CVE-2021-36213
HashiCorp Consul L4 Traffic Failing Open Vulnerability
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.

INFO

Published Date :

July 17, 2021, 6:15 p.m.

Last Modified :

Sept. 14, 2022, 8:58 p.m.

Remotely Exploitable :

Yes !

Impact Score :

3.6

Exploitability Score :

3.9
Affected Products

The following products are affected by CVE-2021-36213 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Hashicorp consul
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-36213.

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

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-36213 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-36213 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Modified Analysis by [email protected]

    Sep. 14, 2022

    Action Type Old Value New Value
    Changed Reference Type https://security.gentoo.org/glsa/202208-09 No Types Assigned https://security.gentoo.org/glsa/202208-09 Third Party Advisory
  • CVE Modified by [email protected]

    Aug. 10, 2022

    Action Type Old Value New Value
    Added Reference https://security.gentoo.org/glsa/202208-09 [No Types Assigned]
  • Initial Analysis by [email protected]

    Jul. 29, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:N/I:P/A:N)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
    Changed Reference Type https://discuss.hashicorp.com/t/hcsec-2021-16-consul-s-application-aware-intentions-deny-action-fails-open-when-combined-with-default-deny-policy/26855 No Types Assigned https://discuss.hashicorp.com/t/hcsec-2021-16-consul-s-application-aware-intentions-deny-action-fails-open-when-combined-with-default-deny-policy/26855 Vendor Advisory
    Changed Reference Type https://github.com/hashicorp/consul/releases/tag/v1.10.1 No Types Assigned https://github.com/hashicorp/consul/releases/tag/v1.10.1 Release Notes, Third Party Advisory
    Changed Reference Type https://www.hashicorp.com/blog/category/consul No Types Assigned https://www.hashicorp.com/blog/category/consul Product, Vendor Advisory
    Added CWE NIST NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:a:hashicorp:consul:*:*:*:*:-:*:*:* versions from (including) 1.9.0 up to (excluding) 1.9.8 *cpe:2.3:a:hashicorp:consul:*:*:*:*:enterprise:*:*:* versions from (including) 1.9.0 up to (excluding) 1.9.8 *cpe:2.3:a:hashicorp:consul:*:*:*:*:-:*:*:* versions from (including) 1.10.0 up to (excluding) 1.10.1 *cpe:2.3:a:hashicorp:consul:*:*:*:*:enterprise:*:*:* versions from (including) 1.10.0 up to (excluding) 1.10.1
  • CVE Modified by [email protected]

    Jul. 19, 2021

    Action Type Old Value New Value
    Changed Description In HashiCorp Consul before 1.10.1 (and Consul Enterprise), xds can generate a situation where a single L7 deny intention (with a default deny policy) results in an allow action. 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.
    Added Reference https://discuss.hashicorp.com/t/hcsec-2021-16-consul-s-application-aware-intentions-deny-action-fails-open-when-combined-with-default-deny-policy/26855 [No Types Assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-36213 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-36213 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.11 }} 0.01%

score

0.43466

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability