CVE-2021-33365

Memory disclosure via failed descriptor cleanup

Published Sep 13, 2021 · Updated Aug 3, 2024

Memory leakage in MP4Box's ISO media parser in GPAC 1.0.1 allows attackers to read process memory by supplying a crafted file. On descriptor-copy failure, gf_isom_get_root_od returns without freeing a partially allocated descriptor and its ESDescriptors list. The attacker must cause MP4Box or embedded libgpac code to process the file; public records do not explain how the retained allocation exposes memory contents.

CVSS severity5.5
Medium
EPSS probability0.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leakage in MP4Box's ISO media parser in GPAC 1.0.1 allows attackers to read process memory by supplying a crafted file. On descriptor-copy failure, gf_isom_get_root_od returns without freeing a partially allocated descriptor and its ESDescriptors list. The attacker must cause MP4Box or embedded libgpac code to process the file; public records do not explain how the retained allocation exposes memory contents.

The record

CVE
CVE-2021-33365
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

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

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)
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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