CVE-2021-29324Public exploit

Process crash via recursive exponentiation parsing

Published Nov 19, 2021 · Updated Aug 3, 2024

Stack overflow in the XS parser in OpenSource Moddable 10.5.0 allows local users to crash the runtime with crafted JavaScript. The fxExponentiationExpression parser recursively processes an attacker-controlled chain of exponentiation operators until the native call stack is exhausted. Execution of the crafted script by the xst interpreter is required, and the demonstrated consequence is a process crash.

CVSS severity7.8
High
EPSS probability0.76%
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

Stack overflow in the XS parser in OpenSource Moddable 10.5.0 allows local users to crash the runtime with crafted JavaScript. The fxExponentiationExpression parser recursively processes an attacker-controlled chain of exponentiation operators until the native call stack is exhausted. Execution of the crafted script by the xst interpreter is required, and the demonstrated consequence is a process crash.

The record

CVE
CVE-2021-29324
Published
Nov 19, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-770, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 19, 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

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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1203Exploitation for Client Execution

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