Twenty six of the top 200 ASX-listed companies are vulnerable to an Apache web server denial of service exploit according to a penetration testing company.
The exploit issues partial content requests to Apache httpd which causes the daemon to swap memory to the file system, eventually triggering a denial of service attack
The attack was released by researcher Kingcope on the Full Disclosure mailing list.
HackLabs director Chris Gatford tested the exploit and found it could work over a 3G mobile connection.
"We edited the exploit script and removed the DoS (Denial of Service) payload and then used it determine how many sites could be affected," Gatford said.
Gatford said 91 of the top 1000 Australian sites listed by Alexa appeared vulnerable to the exploit.
HackLabs said firewalls, intrusion prevention systems or IP table rules could be used to mitigate the attack.
Curl can be run to test exposure to the attack by determining if partial content is supported on by Apache;
curl -H "Range:bytes=1-" -I http://target.com | grep Partial
Apply a patch to add support to turn off partial content.