CVE-2021-45042Network attack vector

Authenticated cluster crash via oversized KV keys

Published Dec 17, 2021 · Updated Aug 4, 2024

Denial of service in affected HashiCorp Vault releases allows remote authenticated users to crash Integrated Storage clusters via KV writes. The KV engine accepted keys larger than 32 KB and persisted them to the Raft log before checking the database limit, so applying the entry panicked Vault. Exploitation requires authentication and KV write permission; affected clusters continue panicking after restart, interrupting secret storage service.

CVSS severity4.9
Medium
EPSS probability1.41%
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 affected HashiCorp Vault releases allows remote authenticated users to crash Integrated Storage clusters via KV writes. The KV engine accepted keys larger than 32 KB and persisted them to the Raft log before checking the database limit, so applying the entry panicked Vault. Exploitation requires authentication and KV write permission; affected clusters continue panicking after restart, interrupting secret storage service.

The record

CVE
CVE-2021-45042
Published
Dec 17, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 17, 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

6.8NIST NVDAV:N/AC:L/Au:S/C:N/I:N/A:C
4.9NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

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 exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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