title: Heap-memory write in FFMPEG
description: A heap out-of-bounds memory write exists in FFMPEG since version 5.1. The size calculation in `build_open_gop_key_points()` goes through all entries in the loop and adds `sc->ctts_data[i].count` to `sc->sample_offsets_count`. This can lead to an integer overflow resulting in a small allocation with `av_calloc()`. An attacker can cause remote code execution via a malicious mp4 file. We recommend upgrading past commit c953baa084607dd1d84c3bfcce3cf6a87c3e6e05
problem types: CWE-122 Heap-based Buffer Overflow
affected:
{
product: FFMPEG
vendor: FFMPEG
versions:
lessThan: unspecified, status: affected, version: 5.1, versionType: custom
lessThan: unspecified, status: affected, version: ab77b878f1205225c6de1370fb0e998dbcc8bc69, versionType: custom
lessThan: c953baa084607dd1d84c3bfcce3cf6a87c3e6e05, status: affected, version: unspecified, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: HIGH
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 9
baseSeverity: CRITICAL
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: NONE
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
version: 3.1
]