CVE-2021-21843

CVE-2021-21843 is a high-severity vulnerability in Gpac with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.

Key facts

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 arithmetic resulting in a heap-based buffer overflow that causes memory corruption. After validating the number of ranges, at [41] the library will multiply the count by the size of the GF_SubsegmentRangeInfo structure. On a 32-bit platform, this multiplication can result in an integer overflow causing the space of the array being allocated to be less than expected. An attacker can convince a user to open a video to trigger this vulnerability.

Frequently asked questions

What is CVE-2021-21843?
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 arithmetic resulting in a heap-based buffer overflow that causes memory corruption. After validating the number of ranges, at [41] the library will multiply the count by the size of the GF_SubsegmentRangeInfo structure. On a 32-bit platform, this multiplication can result in an integer overflow causing the space of the array being allocated to be less than expected. An attacker can convince a user to open a video to trigger this vulnerability.
How severe is CVE-2021-21843?
CVE-2021-21843 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-21843 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21843?
CVE-2021-21843 primarily affects Gpac. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-21843?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-21843 published?
CVE-2021-21843 was published on 2021-08-18 and last updated on 2026-06-17.

References

Affected products (3)

More vulnerabilities in Gpac

All CVEs affecting Gpac →

Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities

Browse all CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities →