Advisory: Range header DoS vulnerability Apache HTTPD 1.3 2.x CVE 2011 3192.
Exploit is in the wild! Be warned!
UPDATE: Apache 2.2.20 has been released and it fixes this vulnerability. Update ASAP!
Please note that on Ubuntu the fix has been backported to Apache 2.2.14-5ubuntu8.6 for 10.4 LTS, and 2.2.8-1ubuntu0.21 for 8.04 LTS.
((enjoy))