The sudo utility allows system administrators to give certain users the ability to run commands as root. A flaw was found in the way sudo handled its blacklist of environment variables. When the "env_reset" option was disabled, a user permitted to run certain commands via sudo could use this flaw to run such a command with one of the blacklisted environment variables set, allowing them to run an arbitrary command with the target user"s privileges. Note: This issue does not affect the default configuration of the sudo package as shipped with Red Hat Enterprise Linux 5. Red Hat would like to thank Todd C. Miller for reporting this issue. Upstream acknowledges Sebastien Macke as the original reporter. All sudo users are advised to upgrade to this updated package, which contains a backported patch to correct this issue.