Samba is a suite of SMB and CIFS client/server programs.
Alin Rad Pop (Secunia Research) reported a vulnerability in Samba within the receive_smb_raw() function in the file lib/util_sock.c when parsing SMB packets, possibly leading to a heap-based buffer overflow via an overly large SMB packet.
A remote attacker could possibly exploit this vulnerability by enticing a user to connect to a malicious server or by sending specially crafted packets to an nmbd server configured as a local or domain master browser, resulting in the execution of arbitrary code.
There is no known workaround at this time.
All Samba users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-fs/samba-3.0.28a-r1"