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.
NVD-CWE-Other