Mozilla NSS NULL Character CA SSL Certificate Validation Security Bypass Vulnerability

Mozilla NSS NULL Character CA SSL Certificate Validation Security Bypass Vulnerability

Mozilla Network Security Services (NSS) is prone to a security-bypass vulnerability because it fails to properly validate the domain name in a signed CA certificate, allowing attackers to substitute malicious SSL certificates for trusted ones.

The NSS library is used by a number of applications, including Mozilla Firefox, Thunderbird, and SeaMonkey.

Successfully exploiting this issue allows attackers to perform man-in-the-middle attacks or impersonate trusted servers, which will aid in further attacks.

NOTE (August 6, 2009): This BID had included a similar issue in Fetchmail, but that issue is now documented in BID 35951 (Fetchmail NULL Character CA SSL Certificate Validation Security Bypass Vulnerability).