CVE-2021-21852

Name: CVE-2021-21852
Creator: NVD / NIST
Published: 2021-08-18T13:15:07.883+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.99%

Last modified Jun 17, 2026

CVE-2021-21852 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Multiple exploitable integer overflow vulnerabilities exist within the MPEG-4 decoding functionality of the GPAC Project on Advanced Content library v1.0.1. A specially crafted MPEG-4 input at “stss” decoder can cause an integer overflow due to unchecked arithmetic resulting in a heap-based buffer overflow that causes memory corruption. EPSS estimates a 1.99% chance of exploitation in the next 30 days.

Description

Multiple exploitable integer overflow vulnerabilities exist within the MPEG-4 decoding functionality of the GPAC Project on Advanced Content library v1.0.1. A specially crafted MPEG-4 input at “stss” decoder can cause an integer overflow due to unchecked arithmetic resulting in a heap-based buffer overflow that causes memory corruption. An attacker can convince a user to open a video to trigger this vulnerability.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

1.99%

78.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Gpac	Gpac	1.0.1

References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1297Exploit, Technical Description, Third Party Advisory
https://www.debian.org/security/2023/dsa-5411
https://www.talosintelligence.com/vulnerability_reports/TALOS-2021-1297Broken Link, Exploit, Technical Description, Third Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1297Exploit, Technical Description, Third Party Advisory
https://www.debian.org/security/2023/dsa-5411
https://www.talosintelligence.com/vulnerability_reports/TALOS-2021-1297Broken Link, Exploit, Technical Description, Third Party Advisory

Timeline

Published: Aug 18, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21852?

How severe is CVE-2021-21852?

CVE-2021-21852 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.99% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21852?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21852?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST