The attacker may be attempting to break into a server by sending an HTTP Authentication string containing many characters.
Some web servers require logins in order to access the content.
This is especially true for applications servers and web servers that allow remote administration. Even though hackers might not know the correct username or password, they can try to specify ones that are longer than the system can handle. Some versions of this software contain a buffer overflow. 876 SCO Unixware i2odialogd Remote Buffer Overflow Vulnerability i2odialogd is shipped with SCO Unixware and installed running as root by default. In its authentication mechanism exists a serious buffer overflow vulnerability.