HTTP 請求必須包含用戶特有的機密，以防止攻擊者發出未經授權的請求。
跨站點偽裝請求 (CSRF) 漏洞會在以下情況下發生：
1. Web 應用程序使用會話 cookie。
2. 應用程序未驗證請求是否經過用戶同意便處理 HTTP 請求。
如果該請求未包含證明其來源的 nonce，則處理該請求的代碼將易受到 CSRF 攻擊（除非它并未更改應用程序的狀態）。這意味著使用會話 cookie 的 Web 應用程序必須采取特殊的預防措施，確保攻擊者無法誘騙用戶提交偽請求。假設有一個 Web 應用程序，它允許管理員修改現有帳戶，如下所示：
public class UserProfileController :Controller
{
public ViewResult SubmitUpdate()
{
// Get the user's existing profile data
ProfileData profile = GetUserProfile();
// Update the user object
profile.EmailAddress = Request.Form["email"];
profile.Password = Request.Form["password"];
SaveUserProfile(profile);
ViewData["message"] = "Your profile was updated.";
return View();
}
}
<body onload="document.getElementById('fm1').submit()">
<form id="fm1" action="http://yoursite/UserProfile/SubmitUpdate" method="post">
<input name="email" value="hacker@somewhere.evil" />
<input name="password" value="powned" />
</form>
</body>
referer 的 HTTP 頭文件。referer 頭文件應該包含參考頁面的 URL，但攻擊者可以偽造，因此無法利用 referer 頭文件確定請求的來源。[1] OWASP 2007 OWASP Top 10
[2] Standards Mapping - OWASP Top 10 2007 - (OWASP 2007) A5 Cross Site Request Forgery (CSRF)
[3] Standards Mapping - OWASP Top 10 2010 - (OWASP 2010) A5 Cross-Site Request Forgery (CSRF)
[4] Standards Mapping - Security Technical Implementation Guide Version 3 - (STIG 3) APP3585 CAT II
[5] Standards Mapping - Security Technical Implementation Guide Version 3.4 - (STIG 3.4) APP3585 CAT II
[6] Standards Mapping - Web Application Security Consortium 24 + 2 - (WASC 24 + 2) Cross-Site Request Forgery
[7] Standards Mapping - Common Weakness Enumeration - (CWE) CWE ID 352
[8] A. Klein Divide and Conquer:HTTP Response Splitting, Web Cache Poisoning Attacks, and Related Topics
[9] Standards Mapping - SANS Top 25 2009 - (SANS 2009) Insecure Interaction - CWE ID 352
[10] Standards Mapping - SANS Top 25 2010 - (SANS 2010) Insecure Interaction - CWE ID 352
[11] Standards Mapping - SANS Top 25 2011 - (SANS Top 25 2011) Insecure Interaction - CWE ID 352
[12] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 - (PCI 1.2) Requirement 6.5.5
[13] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 - (PCI 2.0) Requirement 6.5.9