CVE 2010-0426
sudo 1.6.x before 1.6.9p21 and 1.7.x before 1.7.2p4, when a pseudo-command is enabled, permits a match between the name of the pseudo-command and the name of an executable file in an arbitrary directory, which allows local users to gain privileges via a crafted executable file, as demonstrated by a file named sudoedit in a user's home directory.
See the 
CVE page on Mitre.org
for more details.
