Security Vulnerabilities, CVEs, Published In 2001 (Information Leak)

Classic Cisco IOS 9.1 and later allows attackers with access to the login prompt to obtain portions of the command history of previous users, which may allow the attacker to access sensitive data.

Information disclosure vulnerability in Microsoft Windows 2000 telnet service allows remote attackers to determine the existence of user accounts such as Guest, or log in to the server without specifying the domain name, via a malformed userid.

iptables-save in iptables before 1.2.4 records the "--reject-with icmp-host-prohibited" rule as "--reject-with tcp-reset," which causes iptables to generate different responses than specified by the administrator, possibly leading to an information leak.