tsu doh nimh writes: A zero-day vulnerability in yahoo.com that lets attackers hijack Yahoo! email accounts and redirect users to malicious Web sites offers a fascinating glimpse into the underground market for large-scale exploits. Krebsonsecurity.com writes that the exploit, being sold for $700 by an Egyptian hacker on an exclusive cybercrime forum, targets a “cross-site scripting” (XSS) weakness in yahoo.com that lets attackers steal cookies from Yahoo! Webmail users. Such a flaw would let attackers send or read email from the victim’s account.