CVE-2021-45005Network attack vector

Code execution via reused nested-finally jump lists

Published Feb 14, 2022 · Updated Aug 4, 2024

Heap buffer overflow in Artifex MuJS 1.1.3 allows attackers to crash the interpreter or execute arbitrary code via crafted JavaScript. The compiler reuses a statement JumpList when nested try/finally code emits the same statement repeatedly, so already-patched jump entries are processed again. Exploitation requires MuJS to compile attacker-controlled JavaScript; the out-of-bounds write can interrupt the host process or enable code execution.

CVSS severity9.8
Critical
EPSS probability1.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in Artifex MuJS 1.1.3 allows attackers to crash the interpreter or execute arbitrary code via crafted JavaScript. The compiler reuses a statement JumpList when nested try/finally code emits the same statement repeatedly, so already-patched jump entries are processed again. Exploitation requires MuJS to compile attacker-controlled JavaScript; the out-of-bounds write can interrupt the host process or enable code execution.

The record

CVE
CVE-2021-45005
Published
Feb 14, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 14, 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

Public exploit references

No public exploit references are available in this record.

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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