Sicherheitslücken in libsmb2

libsmb2 before 6.3 Integer Overflow in DCE/RPC NDR Decoder via NetrShareEnum

libsmb2 before 6.3 contains integer overflow vulnerabilities in the DCE/RPC NDR decoder in lib/dcerpc.c that allow heap out-of-bounds reads and writes. A malicious SMB server or machine-in-the-middle on unsigned connections can send crafted NetrShareEnum replies with wrapping actual_count or max_count values when clients call smb2_share_enum_async(), corrupting heap memory.

libsmb2 through 6.2 Heap Out-of-Bounds Read via decode_acl Integer Underflow

libsmb2 through 6.2 contains an integer underflow vulnerability in decode_acl that allows malicious SMB servers to trigger heap out-of-bounds reads via crafted security descriptors. Attackers controlling a server or intercepting unsigned sessions can send an AclSize below 8 in a QUERY_INFO reply, bypassing ACE bounds checks and crashing the client.

libsmb2 through 6.2 Heap Out-of-Bounds Read via File System Info Decoders

libsmb2 through 6.2 contains a heap out-of-bounds read vulnerability in smb2_decode_file_fs_volume_info and smb2_decode_file_fs_attribute_info that allows malicious SMB servers to read past reply buffers. Attackers controlling a server or intercepting unsigned sessions can send crafted QUERY_INFO replies with missing or oversized name lengths to crash the client.

libsmb2 through 6.2 Heap Out-of-Bounds Read via smb2_decode_file_all_info

libsmb2 through 6.2 contains a heap out-of-bounds read vulnerability in smb2_decode_file_all_info that allows malicious SMB servers to crash clients by sending an unchecked FileNameLength. Attackers controlling the server or performing man-in-the-middle on unsigned sessions can return crafted FileAllInformation replies to smb2_stat or smb2_fstat calls, crashing the client.

CVE-2025-57632

libsmb2 6.2+ is vulnerable to Buffer Overflow. When processing SMB2 chained PDUs (NextCommand), libsmb2 repeatedly calls smb2_add_iovector() to append to a fixed-size iovec array without checking the upper bound of v->niov (SMB2_MAX_VECTORS=256). An attacker can craft responses with many chained PDUs to overflow v->niov and perform heap out-of-bounds writes, causing memory corruption, crashes, and potentially arbitrary code execution. The SMB2_OPLOCK_BREAK path bypasses message ID validation.

• Auf 6.2+dfsg-3 aktualisieren