The Samba vfsfruit module uses extended file attributes (EA, xattr) to provide "...enhanced compatibility with Apple SMB clients and interoperability with a Netatalk 3 AFP fileserver." Samba versions prior to 4.13.17, 4.14.12 and 4.15.5 with vfsfruit configured allow out-of-bounds heap read and write via specially crafted extended file attributes. A remote attacker with write access to extended file attributes can execute arbitrary code with the privileges of smbd, typically root.

A flaw was found in the way samba implemented SMB1 authentication. An attacker could use this flaw to retrieve the plaintext password sent over the wire even if Kerberos authentication was required.

A flaw was found in the way Samba maps domain users to local users. An authenticated attacker could use this flaw to cause possible privilege escalation.