The SMTP service in Microsoft Internet Information Services (IIS) 4.0 and 5.0 allows remote attackers to bypass anti-relaying rules and send spam or spoofed messages via encapsulated SMTP addresses, a similar vulnerability to CVE-1999-0682.

CRLF injection vulnerability in the CGI implementation in Microsoft Internet Information Services (IIS) 4.x and 5.x on Windows NT and Windows 2000 allows remote attackers to modify arbitrary uppercase environment variables via a \n (newline) character in an HTTP header.