Argument injection vulnerability in Mozilla Firefox before 2.0.0.5, when running on systems with Thunderbird 1.5 installed and certain URIs registered, allows remote attackers to conduct cross-browser scripting attacks and execute arbitrary commands via shell metacharacters in a mailto URI, which are inserted into the command line that is created when invoking Thunderbird.exe, a similar issue to CVE-2007-3670.
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.