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.
securityreason.com/securityalert/3978
www.securityfocus.com/archive/1/493947/100/0/threaded
www.securityfocus.com/archive/1/494101/100/0/threaded
www.securityfocus.com/bid/28548
www.securitytracker.com/id?1019736
www.securitytracker.com/id?1019737
www.securitytracker.com/id?1019738
www.cynops.de/advisories/AKLINK-SA-2008-002.txt
www.cynops.de/advisories/AKLINK-SA-2008-003.txt
www.cynops.de/advisories/AKLINK-SA-2008-004.txt
www.cynops.de/techzone/http_over_x509.html
www.klink.name/security/aklink-sa-2008-002-outlook-smime.txt
www.klink.name/security/aklink-sa-2008-003-live-mail-smime.txt
www.klink.name/security/aklink-sa-2008-004-office2007-signatures.txt