systemd-tmpfiles in systemd before 237 attempts to support ownership/permission changes on hardlinked files even if the fs.protected_hardlinks sysctl is turned off, which allows local users to bypass intended access restrictions via vectors involving a hard link to a file for which the user lacks write access, as demonstrated by changing the ownership of the /etc/passwd file.
{
"unresolved_ranges": [
{
"cpe": "cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*",
"source": "CPE_FIELD",
"extracted_events": [
{
"last_affected": "8.0"
}
]
},
{
"cpe": "cpe:2.3:o:opensuse:leap:42.3:*:*:*:*:*:*:*",
"source": "CPE_FIELD",
"extracted_events": [
{
"last_affected": "42.3"
}
]
}
]
}{
"cpe": "cpe:2.3:a:systemd_project:systemd:*:*:*:*:*:*:*:*",
"source": "CPE_FIELD",
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "237"
}
]
}