Outlook Web Access (OWA) in Microsoft Exchange 5.5 Server, when used with Internet Explorer, does not properly detect certain inline script, which can allow remote attackers to perform arbitrary actions on a user's Exchange mailbox via an HTML e-mail message.

Outlook Web Access (OWA) in Microsoft Exchange 5.5, SP4 and earlier, allows remote attackers to identify valid user email addresses by directly accessing a back-end function that processes the global address list (GAL).

Outlook Web Access (OWA) in Microsoft Exchange 2000 allows an authenticated user to cause a denial of service (CPU consumption) via a malformed OWA request for a deeply nested folder within the user's mailbox.

Vulnerabilities in RPC servers in (1) Microsoft Exchange Server 2000 and earlier, (2) Microsoft SQL Server 2000 and earlier, (3) Windows NT 4.0, and (4) Windows 2000 allow remote attackers to cause a denial of service via malformed inputs.

Memory leak in NNTP service in Windows NT 4.0 and Windows 2000 allows remote attackers to cause a denial of service (memory exhaustion) via a large number of malformed posts.

An interaction between the Outlook Web Access (OWA) service in Microsoft Exchange 2000 Server and Internet Explorer allows attackers to execute malicious script code against a user's mailbox via a message attachment that contains HTML code, which is executed automatically.

Microsoft Exchange 5.5 2000 allows remote attackers to cause a denial of service (hang) via exceptional BER encodings for the LDAP filter type field, as demonstrated by the PROTOS LDAPv3 test suite.

IIS 5.0 and Microsoft Exchange 2000 allow remote attackers to cause a denial of service (memory allocation error) by repeatedly sending a series of specially formatted URL's.

Buffer overflow in Internet Mail Service (IMS) for Microsoft Exchange 5.5 and 5.0 allows remote attackers to conduct a denial of service via AUTH or AUTHINFO commands.

The installation of Microsoft Exchange 2000 before Rev. A creates a user account with a known password, which could allow attackers to gain privileges, aka the "Exchange User Account" vulnerability.