CVE-2021-46332Public exploit

XS runtime crash via typed-array sort bounds error

Published Jan 20, 2022 · Updated Aug 4, 2024

Out-of-bounds read in Moddable SDK 11.5.0 allows local users to crash the XS runtime by executing crafted JavaScript. During Uint8Array.prototype.sort, a crafted comparator return value causes fxUint8Getter in xs/sources/xsDataView.c to read one byte before its heap allocation. The proof of concept requires execution of attacker-controlled JavaScript and demonstrates an AddressSanitizer abort, not a network-reachable service failure.

CVSS severity7.8
High
EPSS probability0.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds read in Moddable SDK 11.5.0 allows local users to crash the XS runtime by executing crafted JavaScript. During Uint8Array.prototype.sort, a crafted comparator return value causes fxUint8Getter in xs/sources/xsDataView.c to read one byte before its heap allocation. The proof of concept requires execution of attacker-controlled JavaScript and demonstrates an AddressSanitizer abort, not a network-reachable service failure.

The record

CVE
CVE-2021-46332
Published
Jan 20, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499
Attack vector
local
Privileges
Unavailable

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/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.

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo