CVE-2021-30468Network attack vector

Service hang via malformed JSON parsing

Published Jun 16, 2021 · Updated Aug 3, 2024

Uncontrolled resource consumption in Apache CXF before 3.3.11 and 3.4.0 through 3.4.3 allows remote attackers to hang service threads. JsonMapObjectReaderWriter enters a nonterminating parse loop when malformed JSON reaches a web-service endpoint, leaving its request thread consuming CPU indefinitely. No authentication or user interaction is required; each crafted request can pin a processing thread and interrupt service without altering data.

CVSS severity7.5
High
EPSS probability7.02%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in Apache CXF before 3.3.11 and 3.4.0 through 3.4.3 allows remote attackers to hang service threads. JsonMapObjectReaderWriter enters a nonterminating parse loop when malformed JSON reaches a web-service endpoint, leaving its request thread consuming CPU indefinitely. No authentication or user interaction is required; each crafted request can pin a processing thread and interrupt service without altering data.

The record

CVE
CVE-2021-30468
Published
Jun 16, 2021
Updated
Aug 3, 2024
Vendor
The Apache Software Foundation
Product
Apache CXF
Classifications
CWE-835, CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 16, 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?

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

  1. Affected versionversion=Apache CXF <3.4.4 changes=[{"at":"3.3.11","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache CXFversion=Apache CXF <3.4.4 changes=[{"at":"3.3.11","status":"unaffected"}]

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5GitHub Advisory DatabaseCVSS:3.1/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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
CWE-400Uncontrolled Resource Consumption
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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