CVE-2021-41456Public exploitNetwork attack vector

Process crash via unchecked szXmlTo copy

Published Oct 1, 2021 · Updated Aug 4, 2024

Stack buffer overflow in GPAC MP4Box 1.0.1 allows attackers to crash the process by importing a crafted NHML file. In nhmldmx_send_sample, strcpy copies the szXmlTo attribute into a fixed-size stack buffer without enforcing its length. Exploitation requires MP4Box to import attacker-controlled NHML; the oversized write crashes the process, with no reported data impact.

CVSS severity7.5
High
EPSS probability1.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflow in GPAC MP4Box 1.0.1 allows attackers to crash the process by importing a crafted NHML file. In nhmldmx_send_sample, strcpy copies the szXmlTo attribute into a fixed-size stack buffer without enforcing its length. Exploitation requires MP4Box to import attacker-controlled NHML; the oversized write crashes the process, with no reported data impact.

The record

CVE
CVE-2021-41456
Published
Oct 1, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 1, 2021CVE 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

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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)
Vectornetwork
Privilegesunauthenticated
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

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Your stack

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