For the most part, the defense against Cross Site Request Forgery (CSRF)--considered one of the most insidious but least appreciated threats in application security--must come from websites themselves, not ordinary web users. To ensure that criminals can\u2019t trick an unknowing user\u2019s web browser into sending unauthorized requests to the websites where they do online banking or other sensitive activities, web developers must increase the number of times they authenticate customers and make other changes in how sites are programmed.But Jeremiah Grossman, CTO at Whitehat Security and one of the country\u2019s most prominent application security researchers, has a workaround he uses to protect himself online. It involves having two browsers: One, which he calls the \u201cpromiscuous\u201d browser, is the one he uses for ordinary browsing. A second browser is used only for security-critical tasks such as online banking. When Grossman wants to do online banking, he closes his promiscous browser, opens the more prudish one, and does only what he has to do before closing it and going back to his insecure browser.The approach works because then, even if Grossman encounters the CSRF attack while online, the website where he does sensitive activities won\u2019t execute any orders it receives from his browser. "The bad guys are just looking in the off chance someone is logged into that particular website," Grossman says.-Rick CookUpdate: * Security Researcher Reveals His \u2019Promiscuous\u2019 BrowserRelated links:* Cross Site Request Forgery (CSRF): Why a little-known web application vulnerability could cause big problems* Chris Wysopal on Application Security: Is the Backdoor Threat the Next Big Threat to Applications?