In an online post, Eric Maurice, manager for security in Oracle's global technology business unit, explained that the alert is the first since Oracle introduced its quarterly Critical Patch Update process in January 2005. The alert is necessary, he said, because code designed to exploit the vulnerability has been posted online.
The severity of the exploit, which can be seen at Milw0rm.com, is rated 10 out of 10.
"It is remotely exploitable without authentication, ... and it can result in compromising the confidentiality, integrity, and availability of the targeted system," said Maurice.
The vulnerability has been assigned the CVE identifier CVE-2008-3257.
Oracle has posted a workaround to defend against the exploit. The workaround involves altering Apache's httpd.conf file to limit the maximum URL length to less than 4,000 bytes. If that's not feasible, Oracle suggests installing the mod_security Apache module.
Oracle plans to release an out-of-cycle patch to address the issue as soon as the patch is ready.
The exploit code was released July 17, two days after Oracle issued its second-quarter Critical Patch Update.
"Unfortunately, the person(s) who published this vulnerability and associated exploit codes did not contact Oracle before publicly disclosing this issue," said Maurice. "This means that the vulnerability was made public before providing Oracle an opportunity to develop an appropriate fix for this issue and notify its customers."