CVE-2021-32053Network attack vector

Database denial of service via uncached history counts

Published May 10, 2021 · Updated Aug 3, 2024

Denial of service in HAPI FHIR JPA Server before 5.4.0 allows remote attackers to destabilize its database via concurrent history requests. Each _history operation calculates Bundle.total by running SELECT COUNT(pid) over hfj_res_ver, forcing a full index scan instead of using a cached count. A server with many resources becomes unresponsive and unstable when many clients issue these requests concurrently, and database access can remain disabled after traffic stops.

CVSS severity5.3
Medium
EPSS probability1.59%
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 HAPI FHIR JPA Server before 5.4.0 allows remote attackers to destabilize its database via concurrent history requests. Each _history operation calculates Bundle.total by running SELECT COUNT(pid) over hfj_res_ver, forcing a full index scan instead of using a cached count. A server with many resources becomes unresponsive and unstable when many clients issue these requests concurrently, and database access can remain disabled after traffic stops.

The record

CVE
CVE-2021-32053
Published
May 10, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 10, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

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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