httputils.rb in WEBrick in Ruby 1.8.1 and 1.8.5, as used in Red Hat Enterprise Linux 4 and 5, allows remote attackers to cause a denial of service (CPU consumption) via a crafted HTTP request. NOTE: this issue exists because of an incomplete fix for CVE-2008-3656.

Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value function in WEBrick::HTTP::DefaultFileHandler in WEBrick in Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 allows context-dependent attackers to cause a denial of service (CPU consumption) via a crafted HTTP request that is processed by a backtracking regular expression.