Mozilla Firefox Multiple Vulnerabilities Fixed in 3.0.13 and 3.5.0

Description

Mozilla Firefox versions before 3.0.13 and 3.5.0 are affected by multiple vulnerabilities:

• Compromise of SSL-protected communication (MFSA 2009-42). A mismatch has been reported in the treatment of domain names in SSL certificates between SSL clients and the Certificate Authorities (CA) which issue server certificates. In particular, if a malicious person requested a certificate for a host name with an invalid null character in it most CAs would issue the certificate if the requester owned the domain specified after the null, while most SSL clients (browsers) ignored that part of the name and used the unvalidated part in front of the null. This made it possible for attackers to obtain certificates that would function for any site they wished to target. These certificates could be used to intercept and potentially alter encrypted communication between the client and a server such as sensitive bank account transactions.
• Heap overflow in certificate regexp parsing (MFSA 2009-43). A heap overflow vulnerability has been reported in the code that handles regular expressions in certificate names. This vulnerability could be used to compromise the browser and run arbitrary code by presenting a specially crafted certificate to the client. This code provided compatibility with the non-standard regular expression syntax historically supported by Netscape clients and servers. With version 3.5 Firefox switched to the more limited industry-standard wildcard syntax instead and is not vulnerable to this flaw.