The S/MIME specification allows a Cipher Block Chaining (CBC) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAIL.

The OpenPGP specification allows a Cipher Feedback Mode (CFB) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAIL. NOTE: third parties report that this is a problem in applications that mishandle the Modification Detection Code (MDC) feature or accept an obsolete packet type, not a problem in the OpenPGP specification

Microsoft Outlook 2007, Microsoft Outlook 2010, Microsoft Outlook 2013, Microsoft Outlook 2016, and Microsoft Office 2016 Click-to-Run allow an elevation of privilege vulnerability due to how the format of incoming message is validated, aka "Microsoft Outlook Elevation of Privilege Vulnerability".

Heap-based buffer overflow in Microsoft Outlook 2002 SP3, 2003 SP3, and 2007 SP2, when Online Mode for an Exchange Server is enabled, allows remote attackers to execute arbitrary code via a crafted e-mail message, aka "Heap Based Buffer Overflow in Outlook Vulnerability."

Microsoft Office Outlook 2002 SP3, 2003 SP3, and 2007 SP1 and SP2 does not properly verify e-mail attachments with a PR_ATTACH_METHOD property value of ATTACH_BY_REFERENCE, which allows user-assisted remote attackers to execute arbitrary code via a crafted message, aka "Microsoft Outlook SMB Attachment Vulnerability."

Microsoft Crypto API 5.131.2600.2180 through 6.0, as used in Outlook, Windows Live Mail, and Office 2007, performs Certificate Revocation List (CRL) checks by using an arbitrary URL from a certificate embedded in a (1) S/MIME e-mail message or (2) signed document, which allows remote attackers to obtain reading times and IP addresses of recipients, and port-scan results, via a crafted certificate with an Authority Information Access (AIA) extension.

Argument injection vulnerability involving Microsoft Outlook and Outlook Express, when certain URIs are registered, allows remote attackers to conduct cross-browser scripting attacks and execute arbitrary commands via shell metacharacters in an unspecified URI, which are inserted into the command line when invoking the handling process, a similar issue to CVE-2007-3670.

The Microsoft Office Outlook Recipient ActiveX control (ole32.dll) in Windows XP SP2 allows remote attackers to cause a denial of service (Internet Explorer 7 hang) via crafted HTML.

Microsoft email clients in Outlook, Exchange, and Windows Messaging automatically respond to Read Receipt and Delivery Receipt tags, which could allow an attacker to flood a mail system with responses by forging a Read Receipt request that is redirected to a large distribution list.

The Microsoft Active Setup ActiveX component in Internet Explorer 4.x and 5.x allows a remote attacker to install software components without prompting the user by stating that the software's manufacturer is Microsoft.