This indicates an attack attempt to exploit a Code Injection Vulnerability in NetBSD tnftp.
The vulnerability is due to an input validation error while parsing a crafted HTTP response. A remote attacker could exploit this to execute arbitrary code within the context of the application, via a crafted HTTP response.
NetBSD Foundation tnftp prior to tnftp-20141031
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.