CVE-2021-21856

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-08-18 · updated 2026-06-17
Weakness: CWE-680

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 can cause an integer overflow due to unchecked addition 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.

Affected products

GPAC: 1.0.1

References

https://talosintelligence.com/vulnerability_reports/TALOS-2021-1299
https://talosintelligence.com/vulnerability_reports/TALOS-2021-1299

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