CVE-2023-30421Public exploit

Service interruption via unbounded numeric parsing

Published Apr 19, 2025 · Updated Apr 21, 2025

Inefficient numeric parsing in mjson 1.2.7 allows attackers to interrupt service by supplying a crafted digit string to mystrtod. The loop in mystrtod executes 1,622,094,001 iterations for the demonstrated input, failing to bound the work required for a numeric token. The input must reach an application path that invokes the library's JSON parser; successful triggering monopolizes CPU for an extended period rather than corrupting data.

CVSS severity2.9
Low
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Inefficient numeric parsing in mjson 1.2.7 allows attackers to interrupt service by supplying a crafted digit string to mystrtod. The loop in mystrtod executes 1,622,094,001 iterations for the demonstrated input, failing to bound the work required for a numeric token. The input must reach an application path that invokes the library's JSON parser; successful triggering monopolizes CPU for an extended period rather than corrupting data.

The record

CVE
CVE-2023-30421
Published
Apr 19, 2025
Updated
Apr 21, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-407, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 19, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 21, 2025Record 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 vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

2.9MITRECVSS:3.1/AV:L/AC:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-407Inefficient Algorithmic Complexity
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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