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Certificate Authority

MS09-056: Addressing the X.509 CryptoAPI ASN.1 security vulnerabilities

Monday, October 12, 2009

MS09-056 addresses two vulnerabilities that affect how the Windows CryptoAPI parses X.509 digital certificates. Applications on the Windows platform as well as Windows components such as the WinHTTP API can call into the CryptoAPI which provides cryptographic services to validate digital certificates. Internet Explorer, for instance, uses the CryptoAPI to parse and validate the certificate of remote web servers while browsing.