The (1) CertGetCertificateChain, (2) CertVerifyCertificateChainPolicy, and (3) WinVerifyTrust APIs within the CryptoAPI for Microsoft products including Microsoft Windows 98 through XP, Office for Mac, Internet Explorer for Mac, and Outlook Express for Mac, do not properly verify the Basic Constraints of intermediate CA-signed X.509 certificates, which allows remote attackers to spoof the certificates of trusted sites via a man-in-the-middle attack for SSL sessions, as originally reported for Internet Explorer and IIS.

Buffer overflow in the S/MIME Parsing capability in Microsoft Outlook Express 5.5 and 6.0 allows remote attackers to execute arbitrary code via a digitally signed email with a long "From" address, which triggers the overflow when the user views or previews the message.

Buffer overflow in Microsoft Outlook Express 5.0, 5.5, and 6.0 allows remote attackers to cause a denial of service (crash) via a long <A HREF> link.

Outlook Express 6.0 does not delete messages from dbx files, even when a user empties the Deleted items folder, which allows local users to read other users email.

The IMAP Client for Sylpheed 0.8.11 allows remote malicious IMAP servers to cause a denial of service (crash) via certain large literal size values that cause either integer signedness errors or integer overflow errors.

The IMAP Client for Outlook Express 6.00.2800.1106 allows remote malicious IMAP servers to cause a denial of service (crash) via certain large literal size values that cause either integer signedness errors or integer overflow errors.

Microsoft Outlook Express 6.0 and Outlook 2000, with the security zone set to Internet Zone, allows remote attackers to execute arbitrary programs via an HTML email with the CODEBASE parameter set to the program, a vulnerability similar to CAN-2002-0077.

Microsoft Outlook Express 5.5 and 6 allows attackers to cause a denial of service (application crash) via a malformed e-mail header.

The MHTML protocol handler in Microsoft Outlook Express 5.5 SP2 through Outlook Express 6 SP1 allows remote attackers to bypass domain restrictions and execute arbitrary code, as demonstrated on Internet Explorer using script in a compiled help (CHM) file that references the InfoTech Storage (ITS) protocol handlers such as (1) ms-its, (2) ms-itss, (3) its, or (4) mk:@MSITStore, aka the "MHTML URL Processing Vulnerability."

Unknown versions of Internet Explorer and Outlook allow remote attackers to spoof a legitimate URL in the status bar via A HREF tags with modified "alt" values that point to the legitimate site, combined with an image map whose href points to the malicious site, which facilitates a "phishing" attack.

Outlook Express 6.0, when sending multipart e-mail messages using the "Break apart messages larger than" setting, leaks the BCC recipients of the message to the addresses listed in the To and CC fields, which may allow remote attackers to obtain sensitive information.

Microsoft Outlook Express 6.0 allows remote attackers to bypass intended access restrictions, load content from arbitrary sources into the Outlook context, and facilitate phishing attacks via a "BASE HREF" with the target set to "_top".

Stack-based buffer overflow in the news reader for Microsoft Outlook Express (MSOE.DLL) 5.5 SP2, 6, and 6 SP1 allows remote malicious NNTP servers to execute arbitrary code via a LIST response with a long second field.

Microsoft Outlook Express 6.0 leaks the default news server account when a user responds to a "watched" conversation thread, which could allow remote attackers to obtain sensitive information.

The Outlook Express Address Book control, when using Internet Explorer 6, allows remote attackers to cause a denial of service (NULL dereference and browser crash) by creating the OutlookExpress.AddressBook COM object, which is not intended for use within Internet Explorer.

Buffer overflow in the HTML library used by Internet Explorer, Outlook Express, and Windows Explorer via the res: local resource protocol.

A component in Microsoft Outlook Express 6 allows remote attackers to bypass domain restrictions and obtain sensitive information via redirections with the mhtml: URI handler, as originally reported for Internet Explorer 6 and 7, aka "URL Redirect Cross Domain Information Disclosure Vulnerability."

Buffer overflow in Microsoft Outlook Express 5.5 and 6 allows remote attackers to execute arbitrary code via a crafted Windows Address Book (WAB) file containing "certain Unicode strings" and modified length values.

Microsoft HTML control as used in (1) Internet Explorer 5.0, (2) FrontPage Express, (3) Outlook Express 5, and (4) Eudora, and possibly others, allows remote malicious web site or HTML emails to cause a denial of service (100% CPU consumption) via large HTML form fields such as text inputs in a table cell.

Microsoft Outlook Express before 4.72.3612.1700 allows a malicious user to send a message that contains a .., which can inadvertently cause Outlook to re-enter POP3 command mode and cause the POP3 session to hang.