The MITRE CVE dictionary describes this issue as:
The CIFS filesystem in the Linux kernel before 2.6.22, when Unix extension support is enabled, does not honor the umask of a process, which allows local users to gain privileges.
Find out more about CVE-2007-3740 from the
MITRE CVE dictionary dictionary and
This issue did not affect the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 2.1 or 3.