CVE-2021-38951Network attack vector

Remote CPU exhaustion via crafted request

Published Dec 9, 2021 · Updated Sep 16, 2024

Denial of service in IBM WebSphere Application Server 7.0, 8.0, 8.5, and 9.0 allows remote attackers to exhaust CPU via a specially-crafted request. IBM has not disclosed the specific request-processing component or operation that mis-handles the input; the published mechanism is limited to a crafted request driving CPU consumption. The unauthenticated network condition can consume all available CPU and interrupt server availability, with no reported confidentiality or integrity impact.

CVSS severity7.5
High
EPSS probability1.52%
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 IBM WebSphere Application Server 7.0, 8.0, 8.5, and 9.0 allows remote attackers to exhaust CPU via a specially-crafted request. IBM has not disclosed the specific request-processing component or operation that mis-handles the input; the published mechanism is limited to a crafted request driving CPU consumption. The unauthenticated network condition can consume all available CPU and interrupt server availability, with no reported confidentiality or integrity impact.

The record

CVE
CVE-2021-38951
Published
Dec 9, 2021
Updated
Sep 16, 2024
Vendor
IBM
Product
IBM WebSphere Application Server
Classifications
T1499.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 9, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.0
  2. Affected versionversion=8.0
  3. Affected versionversion=8.5
  4. Affected versionversion=9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · IBM WebSphere Application Serverversion=7.0; version=8.0; version=8.5; version=9.0

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5IBMCVSS:3.0/AV:N/AC:L/PR:N/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 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

T1499.001OS Exhaustion

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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