The host is installed with Mozilla Firefox before 34.0, Firefox ESR 31.x before 31.3 or Thunderbird before 31.3 on OS X 10.10 (Yosemite) and is prone to an information disclosure vulnerability. A flaw is present in the OS X 10.10 (Yosemite), in which logging was turned on by default for some applications that use a custom memory allocator. Successful exploitation allows attackers to obtain sensitive information such as usernames, passwords and other inputed data being saved to a log file on the local system.