This indicates an attack attempt to exploit a Denial of Service Vulnerability in Memcached Project Memcached.
A remote attacker could exploit this vulnerability by sending a crafted lru mode or lru temp_ttl command to a vulnerable Memcached server. Successful exploitation would result in denial-of-service conditions.
Memcached Project Memcached prior to 1.5.14
Denial of Service: Remote attackers can crash vulnerable systems.
Apply the most recent upgrade or patch from the vendor.