Microsoft Communicator 2007 R2, Lync 2010, Lync 2010 Attendee, and Lync Server 2013 do not properly handle objects in memory, which allows remote attackers to execute arbitrary code via an invitation that triggers access to a deleted object, aka "Lync RCE Vulnerability."

Cross-site scripting (XSS) vulnerability in Microsoft InfoPath 2007 SP2 and SP3 and 2010 SP1, Communicator 2007 R2, Lync 2010 and 2010 Attendee, SharePoint Server 2007 SP2 and SP3 and 2010 SP1, Groove Server 2010 SP1, Windows SharePoint Services 3.0 SP2, SharePoint Foundation 2010 SP1, and Office Web Apps 2010 SP1 allows remote attackers to inject arbitrary web script or HTML via a crafted string, aka "HTML Sanitization Vulnerability."

The toStaticHTML API (aka the SafeHTML component) in Microsoft Internet Explorer 8 and 9, Communicator 2007 R2, and Lync 2010 and 2010 Attendee does not properly handle event attributes and script, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via a crafted HTML document, aka "HTML Sanitization Vulnerability."

Microsoft Communicator allows remote attackers to cause a denial of service (application or device outage) via instant messages containing large numbers of emoticons.

Microsoft Communicator, and Communicator in Microsoft Office 2010 beta, allows remote attackers to cause a denial of service (memory consumption) via a large number of SIP INVITE requests, which trigger the creation of many sessions.

Unspecified vulnerability in Microsoft Office Communications Server (OCS), Office Communicator, and Windows Live Messenger allows remote attackers to cause a denial of service (crash) via a crafted Real-time Transport Control Protocol (RTCP) receiver report packet.

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.