A security researcher has uncovered a critical bug affecting Apple Safari that could be exploited to run malicious code on Windows computers.
The discovery of the flaw is credited to researcher Krystian Kloskowski. According to an advisory from Danish security firm Secunia, the vulnerability is due to an error in the handling of parent Windows and can result in a function call using an invalid pointer.
"This can be exploited to execute arbitrary code when a user e.g. visits a specially crafted web page and closes opened pop-up windows," Secunia wrote in its advisory. "The vulnerability is confirmed in Safari version 4.0.5 for Windows. Other versions may also be affected."
US-CERT warned that exploit code for the vulnerability is publicly available and that, by persuading a victim to view an HTML document such as a Web page or e-mail attachment in Apple Safari, an attacker could run arbitrary code with the privileges of the user. Users should avoid unsolicited links in e-mails, instant messages, Web forums or Internet relay chat channels, according to US-CERT.