ldb before 1.1.24, as used in the AD LDAP server in Samba 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3, mishandles string lengths, which allows remote attackers to obtain sensitive information from daemon heap memory by sending crafted packets and then reading (1) an error message or (2) a database value.

The shadow_copy2_get_shadow_copy_data function in modules/vfs_shadow_copy2.c in Samba 3.x and 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3 does not verify that the DIRECTORY_LIST access right has been granted, which allows remote attackers to access snapshots by visiting a shadow copy directory.

Samba 3.x and 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3 supports connections that are encrypted but unsigned, which allows man-in-the-middle attackers to conduct encrypted-to-unencrypted downgrade attacks by modifying the client-server data stream, related to clidfs.c, libsmb_server.c, and smbXcli_base.c.

vfs.c in smbd in Samba 3.x and 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3, when share names with certain substring relationships exist, allows remote attackers to bypass intended file-access restrictions via a symlink that points outside of a share.

The ldb_wildcard_compare function in ldb_match.c in ldb before 1.1.24, as used in the AD LDAP server in Samba 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3, mishandles certain zero values, which allows remote attackers to cause a denial of service (infinite loop) via crafted packets.