how to prevent xss

Prevent Xss,sql attack function

1. Use the character filtering vulnerability to submit malicious js Code. When the user opens the page, execute 2. Enter the image address, css, and other places that are directly executed during page loading, enter malicious javascript [javascript: xxxx]. When you open a page containing images, You can execute javascript. For example, GET s1.game.com/fight/:id indicates sending troops to a user. Although user verification is performed, the source verification is not performed. You only need to

All printed statements, such as echo and print, must be filtered using htmlentities () before printing. This prevents Xss. Note that htmlentities mysql_real_escape_string () must be written in Chinese () Therefore, if an SQL statement is written like this: "select * from cdr where src =". $ userId; must be changed to $ userId = mysql_real_escape_string ($ userId) All printed statements, such as echo and print, must be filtered using htmlentities

The main way to avoid XSS is to filter the content input and output provided by the user, and many languages provide filtering for HTML: You can use the following functions to filter the parameters that appear to be XSS vulnerabilities PHP's Htmlentities () or Htmlspecialchars ().Python's Cgi.escape (). ASP's Server.HTMLEncode (). Asp. NET Server.HTMLEncode () or more powerful Microsoft Anti-Cross Site

Label:Prevent SQL injection. XSS attack/*** Filter Parameters* Parameters accepted @param string $str* @return String*/Public Function actionfilterwords ($STR){$farr = Array ("/"/("Lect|insert|update|delete|\ ' |\/\*|\*|\.\.\/|\.\/|union|into|load_file|outfile|dump/is");$str = Preg_replace ($farr, ", $STR);return $str;}/*** Filter the accepted parameters or arrays, such as $_get,$_post* @param array|string $arr accepted arguments or arrays* @return ar

This article is a translated version of the XSS defense Checklist Https://www.owasp.org/index.php/XSS_%28Cross_Site_Scripting%29_Prevention_Cheat_SheetIntroductionThis article describes a simple positive pattern that properly uses output transcoding or escaping (encoding or escaping) to defend against XSS attacks.Despite the huge amount of XSS attacks, following

Storage-type XSS and Dom-type XSS"Principle of XSS"Storage-Type XSS1, can be long-term storage on the server side2, each user access will be executed JS script, the attacker can only listen to the specified port#攻击利用方法大体等于反射型xss利用# #多出现在留言板等位置* Recommended use of BurpsuiteA, observe the return results, whether to retur

attackers are also gradually industrializing this process, and often can see the phenomenon of bulk peddling of account passwords in envelopes. This has also caused a lot of normal network users a lot of irreparable loss, the damage is also very large.Iv. Prevention of XSSIn the previous article, we introduced the principles and methods of various XSS attacks. As can be seen, XSS is a broad coverage, high

This article is a translated version, please see the original Https://www.owasp.org/index.php/DOM_based_XSS_Prevention_Cheat_SheetIntroductionSpeaking of XSS attacks, there are three accepted forms of Stored, reflected, and DOM Based XSS.XSS prevention Cheatsheet can effectively solve Stored, reflected XSS attacks, this checklist solves the DOM Based XSS attack,

In some cases, we cannot use any ready-made XSS Code and are all filtered out. Therefore, we need to make some judgments and guesses on the filtering rules. Then use some targeted skills to adapt to or bypass the rules. In this example, we use the log function of QQ space/QQ alumni as an example to guess simple filtering rules, and then use the flash containing addCallback to construct a storage-type XSS. D

  First, cross-site scripting attacks are caused by the lack of strict filtering of user input, so we must intercept the possible risks before all the data comes into our web site and database. The Htmlentities () function can be used for illegal

trigger XSS:A POC is used to verify. You can see the effect by visiting Brutelogic.com.br/poc.svgPosture Four: SourceCreate a GIF image that carries a JavaScript payload as a source for a script. This is useful for bypassing the CSP (content security policy) to protect "Script-src '" (that is, the XSS method that does not allow the use of the sample ). But only if we are able to successfully inject in the same domain as shown below.To create such an

data of the victim user, you can use the data to do various bad things, such as logging on to the website as the victim user, and so on.4. XSS prevention XSS prevention can be started from multiple aspects: (1) As described above, the browser itself can identify simple XSS attack strings to prevent simple

I believe that all of you have had this experience when doing penetration testing, obviously an XSS loophole, but there are XSS filtering rules or WAF protection cause we can not successfully use, such as our input 1. Bypassing MAGIC_QUOTES_GPC Magic_quotes_gpc=on is a security setting in PHP that will rotate some special characters, such as ' (single quotes) to \, "(double quotes) to \, \ to \ For example

then add some other Vulnerability Detection scripts. In addition, the judgment is added so that the script can be run at the appropriate time. For example, if the current webpage URL has no parameters, the XSS Vulnerability Detection script of the URL parameter will not be run, it can also greatly improve the script running efficiency. So I wrote a few common variables out, and the function can be called directly without declaring them (the JavaScrip

The first thing to declare is that this article is purely an ignorant view of a little developer without foresight and knowledge, and is intended only for reference in Web system security.1. Reflection Type XSS VulnerabilityIf an application uses dynamic pages to display error messages to the user, it can create a common XSS vulnerability if the system does not filter and process the user-entered content.Ex

field_input_mask ^ [^ %; ") (+ \\=&> ]> ... maxlength $ {name_field_max_length} mask $ {field_input_mask} ...

Many websites now have cross-site scripting vulnerabilities, allowing hackers to take advantage of them. cross-Site attacks can be easily constructed and are very concealed and difficult to detect (usually jump back to the original page immediately

We know that TRACE and TRACK are the HTTP methods used to debug web server connections. the server that supports this method has a Cross-Site scripting vulnerability. When describing various browser defects, the "Cross-Site-Tracing" is referred to

to the target page. This way, if the user enters some HTML script, it will also be treated as plain text, and will not be executed as part of the target page HTML code.3. Cookie TheftWith XSS attacks, attackers can easily steal cookie information from legitimate users. Therefore, for cookies, we can take the following measures. First of all, we want to avoid the disclosure of privacy in the cookie, such as user name, password, etc., secondly, we can