CVE-2021-41865Public exploitNetwork attack vector

Authenticated client crashes via missing proxy configuration

Published Oct 7, 2021 · Updated Aug 4, 2024

Denial of service in HashiCorp Nomad and Nomad Enterprise 1.1.1 through 1.1.5 allows remote authenticated users to crash clients. For a Consul mesh-gateway job using host networking and no proxy block, serviceRegs dereferences the absent proxy configuration while building a Consul service-registration request. Job-submission capability is required; rescheduling the failed allocation can move the malformed job across the cluster and crash additional clients.

CVSS severity6.5
Medium
EPSS probability1.00%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in HashiCorp Nomad and Nomad Enterprise 1.1.1 through 1.1.5 allows remote authenticated users to crash clients. For a Consul mesh-gateway job using host networking and no proxy block, serviceRegs dereferences the absent proxy configuration while building a Consul service-registration request. Job-submission capability is required; rescheduling the failed allocation can move the malformed job across the cluster and crash additional clients.

The record

CVE
CVE-2021-41865
Published
Oct 7, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 7, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NISTCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.5CanonicalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.0NISTAV:N/AC:L/Au:S/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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