The remote Debian host is missing a security-related update.
The Qualys Security team discovered that sudo, a program designed to provide limited super user privileges to specific users, does not properly parse '/proc/[pid]/stat' to read the device number of the tty from field 7 (tty_nr). A sudoers user can take advantage of this flaw on an SELinux-enabled system to obtain full root privileges.
Upgrade the sudo packages. For the stable distribution (jessie), this problem has been fixed in version 1.8.10p3-1+deb8u4.