CVE-2021-33366

Memory retention via unreleased operating-points allocation

Published Sep 13, 2021 · Updated Aug 3, 2024

Memory leak in MP4Box in GPAC 1.0.1 allows attackers to consume process memory by supplying a crafted media file for parsing. In gf_isom_oinf_read_entry, an oversized layer count returns GF_NON_COMPLIANT_BITSTREAM without freeing the allocated operating-points structure. The trigger requires GPAC to parse attacker-supplied media; the public patch shows retained allocation rather than disclosure of memory contents.

CVSS severity5.5
Medium
EPSS probability0.99%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in MP4Box in GPAC 1.0.1 allows attackers to consume process memory by supplying a crafted media file for parsing. In gf_isom_oinf_read_entry, an oversized layer count returns GF_NON_COMPLIANT_BITSTREAM without freeing the allocated operating-points structure. The trigger requires GPAC to parse attacker-supplied media; the public patch shows retained allocation rather than disclosure of memory contents.

The record

CVE
CVE-2021-33366
Published
Sep 13, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-401, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 13, 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

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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:H/I:N/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N

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 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 exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1204.002User Execution: Malicious File

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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