What is CVE-2021-33363?

CVE-2021-33363 is a medium-severity vulnerability in Gpac, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.5/10. Published 2021-09-13.

How severe is CVE-2021-33363?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Gpac

CVE-2021-33363

Memory leak in the infe_box_read function in MP4Box in GPAC 1.0.1 allows attackers to read memory via a crafted file.

Published 2021-09-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.009 (58.8th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 58.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: +0.000

Affected products

Gpac — versions 1.0.1

Weakness classification (CWE)

CWE-401 — Missing Release of Memory after Effective Lifetime

References

github.com/gpac/gpac/issues/1786 (Patch, Third Party Advisory, Issue Tracking)
github.com/gpac/gpac/commit/ec64c7b8966d7e4642d12debb888be5acf18efb9 (Patch, Third Party Advisory)
www.debian.org/security/2023/dsa-5411 (vendor-advisory)

Frequently asked questions

What is CVE-2021-33363?: CVE-2021-33363 is a medium-severity vulnerability in Gpac, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 5.5/10. Published 2021-09-13.
How severe is CVE-2021-33363?: Medium severity. CVSS v3 base score is 5.5 out of 10.