The LDAP server in the AD domain controller in Samba 4.x before 4.1.22 does not check return values to ensure successful ASN.1 memory allocation, which allows remote attackers to cause a denial of service (memory consumption and daemon crash) via crafted packets.

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.

The Netlogon server implementation in smbd in Samba 3.5.x and 3.6.x before 3.6.25, 4.0.x before 4.0.25, 4.1.x before 4.1.17, and 4.2.x before 4.2.0rc5 performs a free operation on an uninitialized stack pointer, which allows remote attackers to execute arbitrary code via crafted Netlogon packets that use the ServerPasswordSet RPC API, as demonstrated by packets reaching the _netr_ServerPasswordSet function in rpc_server/netlogon/srv_netlog_nt.c.

Samba 4.0.x before 4.0.24, 4.1.x before 4.1.16, and 4.2.x before 4.2rc4, when an Active Directory Domain Controller (AD DC) is configured, allows remote authenticated users to set the LDB userAccountControl UF_SERVER_TRUST_ACCOUNT bit, and consequently gain privileges, by leveraging delegation of authority for user-account or computer-account creation.

NetBIOS name services daemon (nmbd) in Samba 4.0.x before 4.0.21 and 4.1.x before 4.1.11 allows remote attackers to execute arbitrary code via unspecified vectors that modify heap memory, involving a sizeof operation on an incorrect variable in the unstrcpy macro in string_wrappers.h.

The push_ascii function in smbd in Samba 3.6.x before 3.6.24, 4.0.x before 4.0.19, and 4.1.x before 4.1.9 allows remote authenticated users to cause a denial of service (memory corruption and daemon crash) via an attempt to read a Unicode pathname without specifying use of Unicode, leading to a character-set conversion failure that triggers an invalid pointer dereference.

The sys_recvfrom function in nmbd in Samba 3.6.x before 3.6.24, 4.0.x before 4.0.19, and 4.1.x before 4.1.9 allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a malformed UDP packet.

The internal DNS server in Samba 4.x before 4.0.18 does not check the QR field in the header section of an incoming DNS message before sending a response, which allows remote attackers to cause a denial of service (CPU and bandwidth consumption) via a forged response packet that triggers a communication loop, a related issue to CVE-1999-0103.

Samba 3.6.6 through 3.6.23, 4.0.x before 4.0.18, and 4.1.x before 4.1.8, when a certain vfs shadow copy configuration is enabled, does not properly initialize the SRV_SNAPSHOT_ARRAY response field, which allows remote authenticated users to obtain potentially sensitive information from process memory via a (1) FSCTL_GET_SHADOW_COPY_DATA or (2) FSCTL_SRV_ENUMERATE_SNAPSHOTS request.