Buffer Overflows and Network Issues in Multi-Homed Servers

In this column, we look at buffer overflows in ircd, ePerl, MIT Kerberos 4 and 5, ascdc, and slrn; temporary file problems in MIT Kerberos 4 and 5, the GNU C Library, and the Athena widget libraries; other problems with proftpd . . . In this column, we look at buffer overflows in ircd, ePerl, MIT Kerberos 4 and 5, ascdc, and slrn; temporary file problems in MIT Kerberos 4 and 5, the GNU C Library, and the Athena widget libraries; other problems with proftpd under Debian, Midnight Commander, Cisco Aironet 340 Bridges, and man2html; and a discussion of loopback devices and multi-homed routing.

Some operating systems when configured with two or more network interfaces (multi-homed) will deliver packets received from a network interface to the loopback interface. This is a not a bug in the TCP/IP stack of these operating systems. It is an unexpected result of following the applicable Internet standards. Systems that this affects include FreeBSD, NetBSD, and OpenBSD. It is not clear which Linux configurations, if any, are vulnerable.