A malicious application may be able to overwrite arbitrary files. This issue is fixed in macOS Big Sur 11.4, Security Update 2021-004 Mojave. An issue with path validation logic for hardlinks was addressed with improved path sanitization.
[
{
"product": "macOS",
"vendor": "Apple",
"versions": [
{
"lessThan": "11.4",
"status": "affected",
"version": "unspecified",
"versionType": "custom"
}
]
},
{
"product": "macOS",
"vendor": "Apple",
"versions": [
{
"lessThan": "2021",
"status": "affected",
"version": "unspecified",
"versionType": "custom"
}
]
}
]