#VU80033 Missing Authorization in Consul and Consul Enterprise - CVE-2021-41803

Vulnerability identifier: #VU80033

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-41803

CWE-ID: CWE-862

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Consul
Server applications / Other server solutions
Consul Enterprise
Server applications / Other server solutions

Vendor: HashiCorp

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to improper input validation when handling auto-config requests. A remote authenticated user can craft an auto-config request that allows the TLS certificate and ACL token to be generated for a node name not intended by the operator. This forces Consul to store unintended information, which can be repeatedly abused to cause an authenticated denial of service attack from a malicious operator.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Consul: 1.8.1 - 1.8.19, 1.9.0 - 1.9.17, 1.10.0 - 1.13.1

Consul Enterprise: 1.8.1 - 1.8.19, 1.9.0 - 1.9.17, 1.10.0 - 1.13.1

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External links
https://discuss.hashicorp.com/t/hcsec-2022-19-consul-auto-config-jwt-authorization-missing-input-validation/44627

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.