CVE-2021-27568Public exploitNetwork attack vector

Denial of service via malformed floating-point numbers

Published Feb 23, 2021 · Updated Aug 3, 2024

Improper exception handling in netplex json-smart-v1 through 2015-10-23 and json-smart-v2 through 2.4 allows attackers to crash applications. JSONParserBase.extractFloat passes malformed numeric tokens such as '-.' to Java floating-point conversion without translating NumberFormatException into ParseException. An application must parse attacker-controlled JSON without catching the unchecked exception; the demonstrated consequence is interruption of the consuming application.

CVSS severity5.9
Medium
EPSS probability2.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper exception handling in netplex json-smart-v1 through 2015-10-23 and json-smart-v2 through 2.4 allows attackers to crash applications. JSONParserBase.extractFloat passes malformed numeric tokens such as '-.' to Java floating-point conversion without translating NumberFormatException into ParseException. An application must parse attacker-controlled JSON without catching the unchecked exception; the demonstrated consequence is interruption of the consuming application.

The record

CVE
CVE-2021-27568
Published
Feb 23, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-754, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 23, 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

5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
4.3NIST NVDAV:N/AC:M/Au:N/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.

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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 exploitPublished

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions
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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