Internet Explorer SSL Vulnerability :: essays research papers

AbstractInternet adventurers implementation of SSL contains a vulnerability that allows for an active, undetected, part in the middle attack. No dialogsare shown, no warnings are given.======================================================================== translationIn the normal case, the administrator of a meshing site readiness wish to providesecure communication via SSL. To do so, the administrator generates a enfranchisement and has it sign(a) by a Certificate Authority. The generated credential should incline the uniform resource locator of the secure web site in the Common bring infield of the Distinguished Name section.The CA verifies that the administrator legitimately owns the URL in the CNfield, signs the corroboration, and gives it back. Assuming theadministrator is trying to secure www.thoughtcrime.org, we now postulate thefollowing present structureCERT - Issuer VeriSign / Subject VeriSign- CERT - Issuer VeriSign / Subject www.thoughtcrime.orgWhen a web bro wser receives this, it should roam that the CN fieldmatches the domain it just connected to, and that its sign-language(a) using aknown CA certificate. No man in the middle attack is possible because itshould not be possible to replace a certificate with a valid CN and avalid touching.However, on that point is a slightly more complicated scenario. Sometimes it isconvenient to put signing authority to more localized authorities.In this case, the administrator of www.thoughtcrime.org would describe a chainof certificates from the localized authorityIssuer VeriSign / Subject VeriSign- Issuer VeriSign / Subject intermediate CA- Issuer Intermediate CA / Subject www.thoughtcrime.orgWhen a web browser receives this, it should verify that the CN field ofthe leaf certificate matches the domain it just connected to, that itssigned by the intermediate CA, and that the intermediate CA is signed by aknown CA certificate. Finally, the web browser should also check that allintermediate cer tificates have valid CA Basic Constraints.You guessed it, Internet Explorer does not check the Basic Constraints.==========================================================================ExploitSo what does this mean? This instrument that as far as IE is concerned, anyonewith a valid CA-signed certificate for ANY domain tooshie generate a validCA-signed certificate for ANY OTHER domain.As the unscrupulous administrator of www.thoughtcrime.org, I can generatea valid certificate and request a signature from VeriSignCERT - Issuer VeriSign / Subject VeriSign- CERT - Issuer VeriSign / Subject www.thoughtcrime.orgThen I generate a certificate for any domain I want, and sign it using myrun-of-the-mill joe-blow CA-signed certificateCERT - Issuer VeriSign / Subject VeriSign- CERT - Issuer VeriSign / Subject www.thoughtcrime.org- CERT - Issuer www.thoughtcrime.org / Subject www.amazon.comSince IE doesnt check the Basic Constraints on the www.thoughtcrime.orgcertificate, it accepts this cert ificate chain as valid forwww.amazon.com.Anyone with any CA-signed certificate (and the equivalent private