CVE-2021-40608Public exploit

Process crash via uninitialized pointer free

Published Jun 28, 2022 · Updated Aug 4, 2024

Use of an uninitialized pointer in GPAC MP4Box 1.0.1 allows local users to crash the command by processing a crafted media file. In gf_hinter_track_finalize, a tx3g pointer can remain uninitialized when gf_isom_text_get_encoded_tx3g rejects a non-text sample entry, yet the caller still passes that pointer to gf_free. Execution requires a user to invoke MP4Box hinting on the file; the demonstrated consequence is an invalid free and process termination, not data access or code execution.

CVSS severity5.5
Medium
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of an uninitialized pointer in GPAC MP4Box 1.0.1 allows local users to crash the command by processing a crafted media file. In gf_hinter_track_finalize, a tx3g pointer can remain uninitialized when gf_isom_text_get_encoded_tx3g rejects a non-text sample entry, yet the caller still passes that pointer to gf_free. Execution requires a user to invoke MP4Box hinting on the file; the demonstrated consequence is an invalid free and process termination, not data access or code execution.

The record

CVE
CVE-2021-40608
Published
Jun 28, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-908, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 28, 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

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/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.

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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

CWE-908Use of Uninitialized Resource
T1204.002User Execution: Malicious File

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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