An exploit that a hacker could use to crash internet servers is being used in the wild. The exploit targets a vulnerability in Berkeley Internet Name Domain (Bind) 9, the most widely used DNS server standard, warned the Internet Systems Consortium (ISC) on Tuesday. ISC is the organization that supports Bind. The hole in Bind 9 has no workaround. Administrators must upgrade to Bind versions 9.4.3-P3, 9.5.1-P3 or 9.6.1-P1 to mitigate the threat. The exploit, which a hacker could use to launch an attack against unpatched master servers, is easily available, warned ISC. "An active remote exploit is in wide circulation at this time," said ISC in an advisory.