CVE-2021-21852Public exploitNetwork attack vector

Memory corruption via overflowing stss entry allocation

Published Aug 18, 2021 · Updated Aug 3, 2024

Heap-based buffer overflow in GPAC 1.0.1 allows attackers to corrupt process memory by convincing a user to open a crafted MPEG-4 file. The stss_box_read function compares a 32-bit entry count with a 64-bit atom size, then performs 32-bit allocation arithmetic that produces an undersized sampleNumbers array. User interaction is required; parsing the file writes 32-bit entries past the heap allocation and crashes the affected process.

CVSS severity8.8
High
EPSS probability1.99%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in GPAC 1.0.1 allows attackers to corrupt process memory by convincing a user to open a crafted MPEG-4 file. The stss_box_read function compares a 32-bit entry count with a 64-bit atom size, then performs 32-bit allocation arithmetic that produces an undersized sampleNumbers array. User interaction is required; parsing the file writes 32-bit entries past the heap allocation and crashes the affected process.

The record

CVE
CVE-2021-21852
Published
Aug 18, 2021
Updated
Aug 3, 2024
Vendor
GPAC Project
Product
GPAC
Classifications
CWE-190, CWE-680, T1204.002, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 18, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=GPAC Project Advanced Content commit a8a8d412dabcb129e695c3e7d861fcc81f608304 ,GPAC Project Advanced Content v1.0.1,

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GPAC Project · GPACversion=GPAC Project Advanced Content commit a8a8d412dabcb129e695c3e7d861fcc81f608304 ,GPAC Project Advanced Content v1.0.1,

Published CVSS scores

8.8Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
CWE-680Integer Overflow to Buffer Overflow
T1204.002User Execution: Malicious File
T1203Exploitation for Client Execution

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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