Rack is a modular Ruby web server interface.
Rack does not properly randomize hash functions to protect against hash collision attacks.
A remote attacker could send a specially crafted form post, possibly resulting in a Denial of Service condition.
There is no known workaround at this time.
All Rack users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=dev-ruby/rack-1.1.3"