The "spiffy-cgi-handlers" egg would convert a nonexistent "Proxy" header to the HTTP_PROXY environment variable, which would allow attacker…

The "spiffy-cgi-handlers" egg would convert a nonexistent "Proxy" header to the HTTP_PROXY environment variable, which would allow attackers to direct CGI programs which use this environment variable to use an attacker-specified HTTP proxy server (also known as a "httpoxy" attack). This affects all versions of spiffy-cgi-handlers before 0.5.