CVE-2021-46327Public exploit

Process crash via reentrant array mutation during sort

Published Jan 20, 2022 · Updated Aug 4, 2024

Denial of service in Moddable SDK 11.5.0 allows local users to crash the XS runtime by executing crafted JavaScript. In fx_Array_prototype_sort, reentrant toString callbacks splice the array during sorting, leaving the function to read an invalid element pointer and trigger a segmentation fault. Execution of a crafted script within the XS runtime is required, and the demonstrated consequence is process termination without reported data disclosure or code execution.

CVSS severity5.5
Medium
EPSS probability0.72%
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 Moddable SDK 11.5.0 allows local users to crash the XS runtime by executing crafted JavaScript. In fx_Array_prototype_sort, reentrant toString callbacks splice the array during sorting, leaving the function to read an invalid element pointer and trigger a segmentation fault. Execution of a crafted script within the XS runtime is required, and the demonstrated consequence is process termination without reported data disclosure or code execution.

The record

CVE
CVE-2021-46327
Published
Jan 20, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 20, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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 vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
5.5NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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 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

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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