Multiple vulnerabilities has been discovered and corrected in samba:

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 (CVE-2010-1635).

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 xffxff security blob length in a Session Setup AndX
request (CVE-2010-1642).

The updated packages provides samba 3.4.8 which is not vulnerable to
these issues.