The chain_reply function in process.c in smbd in Samba before 3.4.8 and 3.5.x before 3.5.2 allows remote attackers to cause a denial of service (NULL pointer dereference and process crash) via a Negotiate Protocol request with a certain 0x0003 field value followed by a Session Setup AndX request with a certain 0x8003 field value.
The reply_sesssetup_and_X_spnego function in sesssetup.c in smbd in Samba before 3.4.8 and 3.5.x before 3.5.2 allows remote attackers to trigger an out-of-bounds read, and cause a denial of service (process crash), via a \xff\xff security blob length in a Session Setup AndX request.
The default configuration of smbd in Samba before 3.3.11, 3.4.x before 3.4.6, and 3.5.x before 3.5.0rc3, when a writable share exists, allows remote authenticated users to leverage a directory traversal vulnerability, and access arbitrary files, by using the symlink command in smbclient to create a symlink containing .. (dot dot) sequences, related to the combination of the unix extensions and wide links options.
smbd in Samba 3.3.11, 3.4.6, and 3.5.0, when libcap support is enabled, runs with the CAP_DAC_OVERRIDE capability, which allows remote authenticated users to bypass intended file permissions via standard filesystem operations with any client.