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Cross-site scripting

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127:, or the plug-in systems on which they rely. Exploiting one of these, attackers fold malicious content into the content being delivered from the compromised site. When the resulting combined content arrives at the client-side web browser, it has all been delivered from the trusted source, and thus operates under the permissions granted to that system. By finding ways of injecting malicious scripts into web pages, an attacker can gain elevated access-privileges to sensitive page content, to session cookies, and to a variety of other information maintained by the browser on behalf of the user. Cross-site scripting attacks are a case of 477:-based user authentication. Many web applications rely on session cookies for authentication between individual HTTP requests, and because client-side scripts generally have access to these cookies, simple XSS exploits can steal these cookies. To mitigate this particular threat (though not the XSS problem in general), many web applications tie session cookies to the IP address of the user who originally logged in, then only permit that IP to use that cookie. This is effective in most situations (if an attacker is only after the cookie), but obviously breaks down in situations where an attacker is behind the same 2089: 264:) XSS vulnerability is a more devastating variant of a cross-site scripting flaw: it occurs when the data provided by the attacker is saved by the server, and then permanently displayed on "normal" pages returned to other users in the course of regular browsing, without proper HTML escaping. A classic example of this is with online message boards where users are allowed to post HTML formatted messages for other users to read. 570:
opening their systems to vulnerabilities. The Firefox NoScript extension enables users to allow scripts selectively from a given page while disallowing others on the same page. For example, scripts from example.com could be allowed, while scripts from advertisingagency.com that are attempting to run on the same page could be disallowed.
232:) cross-site scripting vulnerability is by far the most basic type of web vulnerability. These holes show up when the data provided by a web client, most commonly in HTTP query parameters (e.g. HTML form submission), is used immediately by server-side scripts to parse and display a page of results for and to that user, without properly 308:
The methods of injection can vary a great deal; in some cases, the attacker may not even need to directly interact with the web functionality itself to exploit such a hole. Any data received by the web application (via email, system logs, IM etc.) that can be controlled by an attacker could become an
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does not need to be reloaded). Another problem with script blocking is that many users do not understand it, and do not know how to properly secure their browsers. Yet another drawback is that many sites do not work without client-side scripting, forcing users to disable protection for that site and
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the user knows that they are bad, which is too late. Functionality that blocks all scripting and external inclusions by default and then allows the user to enable it on a per-domain basis is more effective. This has been possible for a long time in Internet Explorer (since version 4) by setting up
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Mutated XSS happens when the attacker injects something that is seemingly safe but is rewritten and modified by the browser while parsing the markup. This makes it extremely hard to detect or sanitize within the website's application logic. An example is rebalancing unclosed quotation marks or even
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A reflected attack is typically delivered via email or a neutral web site. The bait is an innocent-looking URL, pointing to a trusted site but containing the XSS vector. If the trusted site is vulnerable to the vector, clicking the link can cause the victim's browser to execute the injected script.
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security-engineers introduced the term "cross-site scripting" in January 2000. The expression "cross-site scripting" originally referred to the act of loading the attacked, third-party web application from an unrelated attack-site, in a manner that executes a fragment of JavaScript prepared by the
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in order to trick the victim into executing malicious JavaScript code in their browser. Although it is technically not a true XSS vulnerability due to the fact it relies on socially engineering a user into executing code rather than a flaw in the affected website allowing an attacker to do so, it
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Because HTML documents have a flat, serial structure that mixes control statements, formatting, and the actual content, any non-validated user-supplied data included in the resulting page without proper HTML encoding, may lead to markup injection. A classic example of a potential vector is a site
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developers require the use of JavaScript, some web applications are written to allow operation without the need for any client-side scripts. This allows users, if they choose, to disable scripting in their browsers before using the application. In this way, even potentially malicious client-side
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Persistent XSS vulnerabilities can be more significant than other types because an attacker's malicious script is rendered automatically, without the need to individually target victims or lure them to a third-party website. Particularly in the case of social networking sites, the code would be
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element, it won't be shown on the screen. Then suppose that Bob, a member of the dating site, reaches Mallory's profile, which has her answer to the First Date question. Her script is run automatically by the browser and steals a copy of Bob's real name and email directly from his own machine.
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XSS vulnerabilities were originally found in applications that performed all data processing on the server side. User input (including an XSS vector) would be sent to the server, and then sent back to the user as a web page. The need for an improved user experience resulted in popularity of
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to mark scripts in the HTML document as safe to run instead of keeping the policy entirely separate from the page content. As long as trusted nonces only appear on trustworthy scripts, the browser will not run programs from untrusted authors. Some large application providers report having
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The most significant problem with blocking all scripts on all websites by default is substantial reduction in functionality and responsiveness (client-side scripting can be much faster than server-side scripting because it does not need to connect to a remote server and the page or
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For example, suppose there is a dating website where members scan the profiles of other members to see if they look interesting. For privacy reasons, this site hides everybody's real name and email. These are kept secret on the server. The only time a member's real name and
592:(CSP) allows HTML documents to opt in to disabling some scripts while leaving others enabled. The browser checks each script against a policy before deciding whether to run it. As long as the policy only allows trustworthy scripts and disallows 291:
To do this, for the question "Describe your Ideal First Date", Mallory gives a short answer (to appear normal), but the text at the end of her answer is her script to steal names and emails. If the script is enclosed inside a
60:. XSS effects vary in range from petty nuisance to significant security risk, depending on the sensitivity of the data handled by the vulnerable site and the nature of any security mitigation implemented by the site's owner 764: 547:
Some browsers or browser plugins can be configured to disable client-side scripts on a per-domain basis. This approach is of limited value if scripting is allowed by default, since it blocks bad sites only
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There are several escaping schemes that can be used depending on where the untrusted string needs to be placed within an HTML document including HTML entity encoding, JavaScript escaping, CSS escaping, and
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Suppose that Mallory, an attacker, joins the site and wants to figure out the real names of the people she sees on the site. To do so, she writes a script designed to run from other users' browsers when
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flag which allows a web server to set a cookie that is unavailable to client-side scripts. While beneficial, the feature can neither fully prevent cookie theft nor prevent attacks within the browser.
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large", instead of "<b>very</b> large"). Stopping an XSS attack when accepting HTML input from users is much more complex in this situation. Untrusted HTML input must be run through an
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On the 16th of January, 2000, the following names were suggested and bounced around among a small group of Microsoft security engineers: The next day there was consensus – Cross Site Scripting.
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search engine: if one searches for a string, the search string will typically be redisplayed verbatim on the result page to indicate what was searched for. If this response does not properly
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Besides content filtering, other imperfect methods for cross-site scripting mitigation are also commonly used. One example is the use of additional security controls when handling
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Many operators of particular web applications (e.g. forums and webmail) allow users to utilize a limited subset of HTML markup. When accepting HTML input from users (say,
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As the JavaScript code was also processing user input and rendering it in the web page content, a new sub-class of reflected XSS attacks started to appear that was called
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to become the most common publicly reported security vulnerability, with some researchers in 2007 estimating as many as 68% of websites are likely open to XSS attacks.
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There are several issues with this approach, for example sometimes seemingly harmless tags can be left out which when utilized correctly can still result in an XSS
1379: 56:. During the second half of 2007, XSSed documented 11,253 site-specific cross-site vulnerabilities, compared to 2,134 "traditional" vulnerabilities documented by 1252: 1144: 404:. Most web applications that do not need to accept rich data can use escaping to largely eliminate the risk of XSS attacks in a fairly straightforward manner. 336:. In a DOM-based XSS attack, the malicious data does not touch the web server. Rather, it is being reflected by the JavaScript code, fully on the client side. 197:
There is no single, standardized classification of cross-site scripting flaws, but most experts distinguish between at least two primary flavors of XSS flaws:
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XSS vulnerability). The definition gradually expanded to encompass other modes of code injection, including persistent and non-JavaScript vectors (including
1405: 74:. It initially was an attack that was used for breaching data across sites, but gradually started to include other forms of data injection attacks. 1222: 343:
plugins. Prevention strategies for DOM-based XSS attacks include very similar measures to traditional XSS prevention strategies but implemented in
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will share these permissions. Content from URLs where any of these three attributes are different will have to be granted permissions separately.
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XSS vulnerabilities have been reported and exploited since the 1990s. Prominent sites affected in the past include the social-networking sites
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add-on which, in addition to the ability to enable scripts on a per-domain basis, provides some XSS protection even when scripts are enabled.
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its so called "Security Zones", and in Opera (since version 9) using its "Site Specific Preferences". A solution for Firefox and other
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Another popular method is to strip user input of " and ' however this can also be bypassed as the payload can be concealed with
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is not always sufficient to prevent many forms of XSS attacks, security encoding libraries are usually easier to use.
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and/or pattern matching methods to identify malicious codes potentially and secure them using methods like escaping.
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Another defense approach is to use automated tools that will remove XSS malicious code in web pages, these tools use
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L. K. Shar and H. B. K. Tan, "Automated removal of cross site scripting vulnerabilities in web applications,"
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as trusted.  As long as programs only trademark trustworthy values, an attacker who controls a JavaScript
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Security on the web depends on a variety of mechanisms, including an underlying concept of trust known as the
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into web pages viewed by other users. A cross-site scripting vulnerability may be used by attackers to bypass
2330: 1969: 629: 617: 373: 2566: 2522: 2443: 2243: 1951: 1409: 478: 155: 596:, the browser will not run programs from untrusted authors regardless of the HTML document's structure. 2499: 2457: 2113: 1194: 625: 2360: 2078: 621: 434:) will not suffice since the user input needs to be rendered as HTML by the browser (so it shows as " 288:
profile. The script then sends a quick message to her own server, which collects this information.
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scripts could be inserted unescaped on a page, and users would not be susceptible to XSS attacks.
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Hydara, Isatou; Sultan, Abu Bakar Md.; Zulzalil, Hazura; Admodisastro, Novia (February 1, 2015).
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understand the structure of the HTML they produce and automatically pick an appropriate encoder.
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Many validations rely on parsing out (blacklisting) specific "at risk" HTML tags such as the
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have built-in countermeasures against this and other types of attack — for example
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Grossman, Jeremiah; Hansen, Robert; Fogie, Seth; Petkov, Petko D.; Rager, Anton (2007).
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An example of a DOM-based XSS vulnerability is the bug found in 2011 in a number of
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further designed to self-propagate across accounts, creating a type of client-side
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adding quotation marks to unquoted parameters on parameters to CSS font-family.
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still poses the same risks as a regular XSS vulnerability if properly executed.
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applications that had a majority of the presentation logic (maybe written in
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code and contained in web pages (i.e. input validation and escaping). Some
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or reject HTML control characters, a cross-site scripting flaw will ensue.
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parameter, it is stripped from all cross-origin requests. When set with
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Practical JavaScript, DOM Scripting and Ajax Projects via Amazon Reader
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XSSed: Database of Websites Vulnerable to Cross-Site Scripting Attacks
394: 2365: 2320: 2315: 2163: 2131: 1554: 1180: 968: 701:, an open-source penetration testing tool that includes tests for XSS 486: 482: 352: 134: 105: 886:"Twitter users including Sarah Brown hit by malicious hacker attack" 2325: 2283: 2146: 1730:"How Google Is Using Content Security Policy to Mitigate Web Flaws" 558: 369: 364: 182: 159: 71: 2335: 2310: 2273: 1760: 1091:
XSS Attacks: Cross Site Scripting Exploits and Defense (Abstract)
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scripts), causing some confusion to newcomers to the field of
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to reduce susceptibility to XSS vulnerabilities in websites.
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Cross-site scripting attacks use known vulnerabilities in
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cannot cause XSS.  Trusted types are designed to be
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Lock Me Down | Security for the Everyday Developer
938:"Vulnerability Type Distributions in CVE (version 1.1)" 1380:"ModSecurity: Features: PDF Universal XSS Protection" 96:. This states that if content from one site (such as 485:
as the victim, or the victim is changing his or her
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engine to ensure that it does not contain XSS code.
205:. Some sources further divide these two groups into 1605:73% of sites relied on JavaScript in late 2006, in 1253:"XSS (Cross Site Scripting) Prevention Cheat Sheet" 936:Christey, Steve; Martin, Robert A. (May 22, 2007). 395:
Contextual output encoding/escaping of string input
1850:"Can I use... Support tables for HTML5, CSS3, etc" 1680:"Can I use... Support tables for HTML5, CSS3, etc" 998: 607: 185:. Cross-site scripting flaws have since surpassed 2553: 1490:"How to use security zones in Internet Explorer" 573: 70:considers the term cross-site scripting to be a 1005:. Sebastopol, CA: O'Reilly Media, Inc. p.  1374: 1372: 992: 990: 935: 372:is a form of XSS vulnerability that relies on 142:of the targeted domain (taking advantage of a 1977: 432:&lt;b&gt;very&lt;/b&gt; large 219: 1430: 1061: 1059: 1057: 642: 604:successfully deployed nonce-based policies. 407:Performing HTML entity encoding only on the 313:Server-side versus DOM-based vulnerabilities 1823:Mark, Goodwin; Mike, West (April 6, 2016). 1369: 1069:. Web Application Security Consortium. 2005 996: 987: 864:"The origins of Cross-Site Scripting (XSS)" 839:"Happy 10th birthday Cross-Site Scripting!" 817:"Same Origin Policy - Web Security. W3.org" 1984: 1970: 1757:"[CSP] On Reporting and Filtering" 1555:"Should Mac Users Run Antivirus Software?" 578: 19:"XSS" redirects here. For other uses, see 2528:Security information and event management 1054: 272:are in the browser is when the member is 251: 1991: 1822: 1454: 1279:"template - The Go Programming Language" 1250: 1246: 1244: 1142: 958: 861: 1918:The Web Application Security Consortium 1755:Akhawe, Devdatta (September 21, 2015). 1355:"Prevent a cross-site scripting attack" 855: 209:(caused by server-side code flaws) and 2554: 1754: 1705:"Strict CSP - Content Security Policy" 1552: 1352: 1346: 1195:"DOM based XSS prevention cheat sheet" 1122: 909: 884:Arthur, Charles (September 21, 2010). 883: 830: 422:Safely validating untrusted HTML input 389: 2505:Host-based intrusion detection system 1965: 1894:"Preventing XSS in ASP.NET Made Easy" 1876: 1241: 1081: 837:"dross" on MSDN (December 15, 2009). 380: 1807:Information and Software Technology, 1748: 1583:. Sybase. March 2003. Archived from 1511:Lie, Håkon Wium (February 7, 2006). 1431:O'Reilly, Tim (September 30, 2005). 1143:Grossman, Jeremiah (November 2020). 862:Grossman, Jeremiah (July 30, 2006). 746: 530: 276:, and they can't see anyone else's. 2536:Runtime application self-protection 1510: 1408:. OpenAjax Alliance. Archived from 1251:Williams, Jeff (January 19, 2009). 1123:Alcorn, Wade (September 27, 2005). 1036:Information and Software Technology 959:Berinato, Scott (January 1, 2007). 557:-based browsers is the open source 492: 13: 2087: 1870: 1608:"'Most websites' failing disabled" 1455:Zammetti, Frank (April 16, 2007). 1353:Sharma, Anand (February 3, 2004). 770:from the original on June 25, 2008 462: 41:. XSS attacks enable attackers to 14: 2588: 2577:Client-side web security exploits 2468:Security-focused operating system 1933: 1655:"Content Security Policy Level 3" 1382:. Breach Security. Archived from 997:Paco, Hope; Walther, Ben (2008). 2264:Insecure direct object reference 1515:. Opera Software. Archived from 1125:"The Cross-site Scripting Virus" 709:web application security scanner 599:Modern CSP policies allow using 104:(e.g. ftp, http, or https), (2) 2518:Information security management 1842: 1816: 1799: 1774: 1722: 1697: 1672: 1647: 1626: 1599: 1573: 1553:Mogull, Rich (March 18, 2008). 1531: 1504: 1482: 1447: 1424: 1398: 1321: 1296: 1271: 1215: 1201: 1187: 1173: 1159: 1147:. WhiteHat Security. p. 20 1127:. BindShell.net. Archived from 1115: 1023: 616:to check that values have been 608:Emerging defensive technologies 409:five XML significant characters 16:Computer security vulnerability 1513:"Opera 9 Technology Preview 2" 1492:. Microsoft. December 18, 2007 1435:. O'Reilly Media. pp. 4–5 1094:. Syngress. pp. 70, 156. 952: 929: 903: 877: 809: 782: 653:When a cookie is set with the 503:Another mitigation present in 1: 1001:Web Security Testing Cookbook 910:Leyden, John (May 23, 2008). 740: 574:Selectively disabling scripts 428:<b>very</b> large 77: 1209:"Strict Contextual Escaping" 1048:10.1016/j.infsof.2014.07.010 912:"Facebook poked by XSS flaw" 763:. April 2008. pp. 1–3. 430:), output encoding (such as 7: 2572:Hacking (computer security) 2523:Information risk management 2444:Multi-factor authentication 2000:Related security categories 971:. p. 7. Archived from 672: 449:, link and the script tag. 358: 334:-based cross-site scripting 98:https://mybank.example1.com 10: 2593: 2500:Intrusion detection system 2458:Computer security software 2114:Advanced persistent threat 1406:"Ajax and Mashup Security" 1329:"pug-plugin-trusted-types" 646: 582: 496: 466: 362: 220:Non-persistent (reflected) 81: 37:that can be found in some 18: 2399: 2099: 2085: 2079:Digital rights management 1999: 643:SameSite cookie parameter 511:(since version 2.0.0.5), 402:URL (or percent) encoding 2224:Denial-of-service attack 2119:Arbitrary code execution 1782:"Trusted Types Spec WIP" 725:Cross-document messaging 679:Web application security 519:(since version 9.5) and 192: 33:) is a type of security 2434:Computer access control 2386:Rogue security software 2049:Electromagnetic warfare 1541:. Mozilla. May 30, 2008 1255:. OWASP. Archived from 590:Content Security Policy 585:Content Security Policy 579:Content Security Policy 216:(in client-side code). 2480:Obfuscation (software) 2209:Browser Helper Objects 2093: 1952:Reviewing Code for XSS 1914:"Cross Site Scripting" 1461:. Apress. p. 36. 1067:"Cross-site Scripting" 612:Trusted types changes 252:Persistent (or stored) 121:web-based applications 2562:Web security exploits 2475:Data-centric security 2356:Remote access trojans 2091: 1121:Viruses and worms in 665:since version 63 and 467:Further information: 349:JavaScript frameworks 2407:Application security 2301:Privilege escalation 2169:Cross-site scripting 2022:Cybersex trafficking 1993:Information security 1561:. TidBITS Publishing 735:Parameter validation 730:Samy (computer worm) 715:free and open source 594:dynamic code loading 416:web template systems 172:information security 27:Cross-site scripting 21:XSS (disambiguation) 2054:Information warfare 2012:Automotive security 1877:MacKenzie, Thomas. 1825:"Same-site Cookies" 1634:"NoScript Features" 1304:"Google Developers" 940:. MITRE Corporation 689:XML external entity 515:(since version 4), 507:(since version 6), 390:Preventive measures 46:client-side scripts 2567:Injection exploits 2463:Antivirus software 2331:Social engineering 2296:Polymorphic engine 2249:Fraudulent dialers 2154:Hardware backdoors 2094: 1920:. October 13, 2005 1900:. February 6, 2015 1813:pp. 467-478, 2012. 1709:csp.withgoogle.com 1614:. December 6, 2006 1227:www.majorgeeks.com 1181:"JQuery bug #9521" 699:Metasploit Project 669:since version 60. 381:Mutated XSS (mXSS) 374:social engineering 309:injection vector. 94:same-origin policy 88:Same-origin policy 54:same-origin policy 2549: 2548: 2511:Anomaly detection 2416:Secure by default 2269:Keystroke loggers 2204:Drive-by download 2092:vectorial version 2059:Internet security 2007:Computer security 1468:978-1-59059-816-0 1433:"What Is Web 2.0" 1386:on March 23, 2008 1308:Google Developers 1259:on March 18, 2017 1101:978-1-59749-154-9 1016:978-0-596-51483-9 975:on April 18, 2008 707:, an open-source 684:Internet security 531:Disabling scripts 505:Internet Explorer 440:HTML sanitization 2584: 2420:Secure by design 2351:Hardware Trojans 2184:History sniffing 2174:Cross-site leaks 2069:Network security 1986: 1979: 1972: 1963: 1962: 1929: 1927: 1925: 1909: 1907: 1905: 1889: 1887: 1885: 1865: 1864: 1862: 1860: 1846: 1840: 1839: 1837: 1835: 1820: 1814: 1803: 1797: 1796: 1794: 1792: 1778: 1772: 1771: 1769: 1767: 1752: 1746: 1745: 1743: 1741: 1736:. April 22, 2019 1726: 1720: 1719: 1717: 1715: 1701: 1695: 1694: 1692: 1690: 1676: 1670: 1669: 1667: 1665: 1651: 1645: 1644: 1642: 1640: 1630: 1624: 1623: 1621: 1619: 1603: 1597: 1596: 1594: 1592: 1587:on June 18, 2008 1577: 1571: 1570: 1568: 1566: 1550: 1548: 1546: 1535: 1529: 1528: 1526: 1524: 1508: 1502: 1501: 1499: 1497: 1486: 1480: 1479: 1477: 1475: 1451: 1445: 1444: 1442: 1440: 1428: 1422: 1421: 1419: 1417: 1412:on April 3, 2008 1402: 1396: 1395: 1393: 1391: 1376: 1367: 1366: 1364: 1362: 1350: 1344: 1343: 1341: 1339: 1325: 1319: 1318: 1316: 1314: 1300: 1294: 1293: 1291: 1289: 1275: 1269: 1268: 1266: 1264: 1248: 1239: 1238: 1236: 1234: 1219: 1213: 1212: 1205: 1199: 1198: 1191: 1185: 1184: 1177: 1171: 1170: 1163: 1157: 1156: 1154: 1152: 1140: 1138: 1136: 1119: 1113: 1112: 1110: 1108: 1085: 1079: 1078: 1076: 1074: 1063: 1052: 1051: 1027: 1021: 1020: 1004: 994: 985: 984: 982: 980: 956: 950: 949: 947: 945: 933: 927: 926: 924: 922: 907: 901: 900: 898: 896: 881: 875: 874: 872: 870: 859: 853: 852: 847: 845: 834: 828: 827: 825: 823: 813: 807: 806: 804: 802: 786: 780: 779: 777: 775: 769: 758: 750: 717:code library by 694:Browser security 660: 656: 649:Same-site cookie 499:Http-only cookie 493:Http-only cookie 433: 429: 295: 187:buffer overflows 140:security context 138:attacker in the 39:web applications 2592: 2591: 2587: 2586: 2585: 2583: 2582: 2581: 2552: 2551: 2550: 2545: 2395: 2095: 2083: 2074:Copy protection 2064:Mobile security 1995: 1990: 1948:Testing for XSS 1936: 1923: 1921: 1912: 1903: 1901: 1892: 1883: 1881: 1873: 1871:Further reading 1868: 1858: 1856: 1848: 1847: 1843: 1833: 1831: 1821: 1817: 1804: 1800: 1790: 1788: 1780: 1779: 1775: 1765: 1763: 1753: 1749: 1739: 1737: 1728: 1727: 1723: 1713: 1711: 1703: 1702: 1698: 1688: 1686: 1678: 1677: 1673: 1663: 1661: 1653: 1652: 1648: 1638: 1636: 1632: 1631: 1627: 1617: 1615: 1606: 1604: 1600: 1590: 1588: 1579: 1578: 1574: 1564: 1562: 1544: 1542: 1537: 1536: 1532: 1522: 1520: 1519:on May 17, 2008 1509: 1505: 1495: 1493: 1488: 1487: 1483: 1473: 1471: 1469: 1452: 1448: 1438: 1436: 1429: 1425: 1415: 1413: 1404: 1403: 1399: 1389: 1387: 1378: 1377: 1370: 1360: 1358: 1351: 1347: 1337: 1335: 1327: 1326: 1322: 1312: 1310: 1302: 1301: 1297: 1287: 1285: 1277: 1276: 1272: 1262: 1260: 1249: 1242: 1232: 1230: 1229:. July 29, 2014 1221: 1220: 1216: 1207: 1206: 1202: 1193: 1192: 1188: 1179: 1178: 1174: 1167:"DOM based XSS" 1165: 1164: 1160: 1150: 1148: 1134: 1132: 1131:on May 16, 2008 1120: 1116: 1106: 1104: 1102: 1086: 1082: 1072: 1070: 1065: 1064: 1055: 1028: 1024: 1017: 995: 988: 978: 976: 957: 953: 943: 941: 934: 930: 920: 918: 908: 904: 894: 892: 882: 878: 868: 866: 860: 856: 843: 841: 835: 831: 821: 819: 815: 814: 810: 800: 798: 788: 787: 783: 773: 771: 767: 756: 752: 751: 747: 743: 675: 658: 655:SameSite=Strict 654: 651: 645: 637:static analysis 610: 587: 581: 576: 533: 501: 495: 471: 465: 463:Cookie security 431: 427: 424: 397: 392: 383: 367: 361: 315: 293: 254: 222: 195: 90: 82:Main articles: 80: 50:access controls 24: 17: 12: 11: 5: 2590: 2580: 2579: 2574: 2569: 2564: 2547: 2546: 2544: 2543: 2541:Site isolation 2538: 2533: 2532: 2531: 2525: 2515: 2514: 2513: 2508: 2497: 2492: 2487: 2482: 2477: 2472: 2471: 2470: 2465: 2455: 2454: 2453: 2448: 2447: 2446: 2439:Authentication 2431: 2430: 2429: 2428: 2427: 2417: 2414: 2403: 2401: 2397: 2396: 2394: 2393: 2388: 2383: 2378: 2373: 2368: 2363: 2358: 2353: 2348: 2343: 2338: 2333: 2328: 2323: 2318: 2313: 2308: 2303: 2298: 2293: 2292: 2291: 2281: 2276: 2271: 2266: 2261: 2256: 2251: 2246: 2241: 2239:Email spoofing 2236: 2231: 2226: 2221: 2216: 2211: 2206: 2201: 2196: 2191: 2186: 2181: 2179:DOM clobbering 2176: 2171: 2166: 2161: 2159:Code injection 2156: 2151: 2150: 2149: 2144: 2139: 2134: 2126: 2121: 2116: 2111: 2105: 2103: 2097: 2096: 2086: 2084: 2082: 2081: 2076: 2071: 2066: 2061: 2056: 2051: 2046: 2041: 2039:Cyberterrorism 2036: 2031: 2030: 2029: 2027:Computer fraud 2024: 2014: 2009: 2003: 2001: 1997: 1996: 1989: 1988: 1981: 1974: 1966: 1960: 1959: 1954: 1935: 1934:External links 1932: 1931: 1930: 1910: 1890: 1872: 1869: 1867: 1866: 1841: 1829:tools.ietf.org 1815: 1798: 1786:wicg.github.io 1773: 1747: 1721: 1696: 1671: 1646: 1625: 1598: 1572: 1530: 1503: 1481: 1467: 1446: 1423: 1397: 1368: 1345: 1320: 1295: 1270: 1240: 1214: 1200: 1186: 1172: 1158: 1114: 1100: 1080: 1053: 1022: 1015: 986: 951: 928: 902: 876: 854: 829: 808: 781: 744: 742: 739: 738: 737: 732: 727: 722: 711: 702: 696: 691: 686: 681: 674: 671: 647:Main article: 644: 641: 609: 606: 583:Main article: 580: 577: 575: 572: 532: 529: 497:Main article: 494: 491: 481:IP address or 464: 461: 423: 420: 396: 393: 391: 388: 382: 379: 363:Main article: 360: 357: 314: 311: 294:<script> 253: 250: 226:non-persistent 221: 218: 199:non-persistent 194: 191: 148:non-persistent 129:code injection 79: 76: 15: 9: 6: 4: 3: 2: 2589: 2578: 2575: 2573: 2570: 2568: 2565: 2563: 2560: 2559: 2557: 2542: 2539: 2537: 2534: 2529: 2526: 2524: 2521: 2520: 2519: 2516: 2512: 2509: 2506: 2503: 2502: 2501: 2498: 2496: 2493: 2491: 2488: 2486: 2483: 2481: 2478: 2476: 2473: 2469: 2466: 2464: 2461: 2460: 2459: 2456: 2452: 2451:Authorization 2449: 2445: 2442: 2441: 2440: 2437: 2436: 2435: 2432: 2426: 2423: 2422: 2421: 2418: 2415: 2413: 2412:Secure coding 2410: 2409: 2408: 2405: 2404: 2402: 2398: 2392: 2389: 2387: 2384: 2382: 2381:SQL injection 2379: 2377: 2374: 2372: 2369: 2367: 2364: 2362: 2361:Vulnerability 2359: 2357: 2354: 2352: 2349: 2347: 2346:Trojan horses 2344: 2342: 2341:Software bugs 2339: 2337: 2334: 2332: 2329: 2327: 2324: 2322: 2319: 2317: 2314: 2312: 2309: 2307: 2304: 2302: 2299: 2297: 2294: 2290: 2287: 2286: 2285: 2282: 2280: 2277: 2275: 2272: 2270: 2267: 2265: 2262: 2260: 2257: 2255: 2252: 2250: 2247: 2245: 2242: 2240: 2237: 2235: 2232: 2230: 2229:Eavesdropping 2227: 2225: 2222: 2220: 2219:Data scraping 2217: 2215: 2212: 2210: 2207: 2205: 2202: 2200: 2197: 2195: 2192: 2190: 2189:Cryptojacking 2187: 2185: 2182: 2180: 2177: 2175: 2172: 2170: 2167: 2165: 2162: 2160: 2157: 2155: 2152: 2148: 2145: 2143: 2140: 2138: 2135: 2133: 2130: 2129: 2127: 2125: 2122: 2120: 2117: 2115: 2112: 2110: 2107: 2106: 2104: 2102: 2098: 2090: 2080: 2077: 2075: 2072: 2070: 2067: 2065: 2062: 2060: 2057: 2055: 2052: 2050: 2047: 2045: 2042: 2040: 2037: 2035: 2032: 2028: 2025: 2023: 2020: 2019: 2018: 2015: 2013: 2010: 2008: 2005: 2004: 2002: 1998: 1994: 1987: 1982: 1980: 1975: 1973: 1968: 1967: 1964: 1958: 1955: 1953: 1949: 1945: 1941: 1938: 1937: 1919: 1915: 1911: 1899: 1895: 1891: 1880: 1875: 1874: 1855: 1851: 1845: 1830: 1826: 1819: 1812: 1808: 1802: 1787: 1783: 1777: 1762: 1758: 1751: 1735: 1731: 1725: 1710: 1706: 1700: 1685: 1681: 1675: 1660: 1656: 1650: 1635: 1629: 1613: 1609: 1602: 1586: 1582: 1576: 1560: 1556: 1540: 1534: 1518: 1514: 1507: 1491: 1485: 1470: 1464: 1460: 1459: 1450: 1434: 1427: 1411: 1407: 1401: 1385: 1381: 1375: 1373: 1356: 1349: 1334: 1330: 1324: 1309: 1305: 1299: 1284: 1280: 1274: 1258: 1254: 1247: 1245: 1233:September 20, 1228: 1224: 1218: 1211:. Angular.js. 1210: 1204: 1196: 1190: 1182: 1176: 1168: 1162: 1146: 1130: 1126: 1118: 1103: 1097: 1093: 1092: 1084: 1068: 1062: 1060: 1058: 1049: 1045: 1041: 1037: 1033: 1026: 1018: 1012: 1008: 1003: 1002: 993: 991: 974: 970: 966: 962: 955: 939: 932: 917: 913: 906: 895:September 21, 891: 887: 880: 869:September 15, 865: 858: 851: 840: 833: 818: 812: 797: 796: 791: 785: 766: 762: 755: 749: 745: 736: 733: 731: 728: 726: 723: 720: 716: 713:DOMPurify, a 712: 710: 706: 703: 700: 697: 695: 692: 690: 687: 685: 682: 680: 677: 676: 670: 668: 664: 663:Google Chrome 650: 640: 638: 633: 631: 627: 623: 619: 615: 605: 602: 597: 595: 591: 586: 571: 568: 562: 560: 556: 551: 545: 542: 538: 528: 526: 522: 521:Google Chrome 518: 514: 510: 506: 500: 490: 488: 484: 480: 476: 470: 460: 458: 453: 450: 448: 443: 441: 437: 419: 417: 412: 410: 405: 403: 387: 378: 375: 371: 366: 356: 354: 350: 346: 342: 337: 335: 333: 327: 325: 321: 310: 306: 304: 298: 289: 287: 283: 277: 275: 271: 265: 263: 259: 249: 245: 243: 237: 236:the content. 235: 231: 227: 217: 215: 213: 208: 204: 200: 190: 188: 184: 180: 175: 173: 169: 165: 161: 157: 153: 149: 145: 141: 136: 132: 130: 126: 122: 117: 115: 111: 107: 103: 99: 95: 89: 85: 75: 73: 69: 65: 63: 59: 55: 51: 47: 44: 40: 36: 35:vulnerability 32: 28: 22: 2485:Data masking 2168: 2044:Cyberwarfare 1922:. Retrieved 1917: 1902:. Retrieved 1897: 1882:. Retrieved 1857:. Retrieved 1853: 1844: 1832:. Retrieved 1828: 1818: 1810: 1806: 1801: 1789:. Retrieved 1785: 1776: 1764:. Retrieved 1750: 1738:. Retrieved 1733: 1724: 1712:. Retrieved 1708: 1699: 1687:. Retrieved 1683: 1674: 1662:. Retrieved 1658: 1649: 1637:. Retrieved 1628: 1616:. Retrieved 1611: 1601: 1589:. Retrieved 1585:the original 1575: 1563:. Retrieved 1558: 1543:. Retrieved 1533: 1521:. Retrieved 1517:the original 1506: 1494:. Retrieved 1484: 1472:. Retrieved 1457: 1449: 1437:. Retrieved 1426: 1414:. Retrieved 1410:the original 1400: 1388:. Retrieved 1384:the original 1359:. Retrieved 1348: 1336:. Retrieved 1332: 1323: 1311:. Retrieved 1307: 1298: 1286:. Retrieved 1282: 1273: 1261:. Retrieved 1257:the original 1231:. Retrieved 1226: 1217: 1203: 1189: 1175: 1161: 1149:. Retrieved 1133:. Retrieved 1129:the original 1117: 1105:. Retrieved 1090: 1083: 1071:. Retrieved 1039: 1035: 1025: 1000: 977:. Retrieved 973:the original 964: 954: 942:. Retrieved 931: 919:. Retrieved 916:The Register 915: 905: 893:. Retrieved 890:The Guardian 889: 879: 867:. Retrieved 857: 849: 842:. Retrieved 832: 820:. Retrieved 811: 799:. Retrieved 793: 784: 772:. Retrieved 748: 659:SameSite=Lax 652: 634: 622:string value 611: 598: 588: 563: 549: 546: 534: 524: 502: 472: 454: 451: 444: 435: 425: 413: 406: 398: 384: 368: 338: 330: 328: 316: 307: 299: 290: 285: 281: 278: 266: 261: 257: 255: 246: 238: 229: 225: 223: 210: 206: 202: 198: 196: 176: 147: 143: 133: 118: 109: 97: 91: 84:Web security 66: 52:such as the 30: 26: 25: 2425:Misuse case 2259:Infostealer 2234:Email fraud 2199:Data breach 2034:Cybergeddon 1924:October 24, 1904:October 24, 1884:October 24, 1854:caniuse.com 1684:caniuse.com 1263:February 4, 1042:: 170–186. 844:February 9, 822:November 4, 618:trademarked 469:HTTP cookie 457:obfuscation 207:traditional 114:port number 2556:Categories 2490:Encryption 2366:Web shells 2306:Ransomware 2254:Hacktivism 2017:Cybercrime 1766:January 1, 1659:www.w3.org 1539:"NoScript" 1283:golang.org 774:January 1, 741:References 630:blue teams 447:iframe tag 345:JavaScript 320:JavaScript 258:persistent 234:sanitizing 203:persistent 166:, or even 102:URI scheme 78:Background 2321:Shellcode 2316:Scareware 2164:Crimeware 2124:Backdoors 1809:vol. 54, 969:CXO Media 801:March 19, 626:auditable 487:mobile IP 483:web proxy 353:AngularJS 274:signed in 230:reflected 144:reflected 135:Microsoft 106:host name 2495:Firewall 2400:Defenses 2326:Spamming 2311:Rootkits 2284:Phishing 2244:Exploits 1639:March 7, 1612:BBC News 1197:. OWASP. 1169:. OWASP. 765:Archived 673:See also 614:Web APIs 559:NoScript 525:HttpOnly 523:, is an 370:Self-XSS 365:Self-XSS 359:Self-XSS 183:Facebook 160:VBScript 123:, their 72:misnomer 58:Symantec 2336:Spyware 2279:Payload 2274:Malware 2214:Viruses 2194:Botnets 2101:Threats 1761:Dropbox 1618:June 4, 1591:June 4, 1565:June 4, 1559:TidBITS 1545:June 4, 1523:June 4, 1496:June 4, 1474:June 4, 1439:June 4, 1416:June 9, 1390:June 6, 1361:May 29, 1183:. 2011. 1151:June 6, 1135:May 27, 1107:May 28, 1073:May 28, 979:June 7, 944:June 7, 921:May 28, 667:Firefox 537:Web 2.0 509:Firefox 179:Twitter 152:ActiveX 125:servers 62:network 2530:(SIEM) 2507:(HIDS) 2391:Zombie 2128:Bombs 2109:Adware 1859:May 4, 1834:May 4, 1791:May 1, 1740:May 1, 1714:May 1, 1689:May 1, 1664:May 1, 1465:  1338:May 1, 1313:May 1, 1288:May 1, 1098:  1013:  719:Cure53 601:nonces 535:While 513:Safari 475:cookie 341:jQuery 284:visit 262:stored 242:escape 214:-based 43:inject 2376:Worms 2371:Wiper 2289:Voice 2137:Logic 1940:OWASP 1734:eWEEK 1357:. IBM 795:OWASP 768:(PDF) 761:Yahoo 757:(PDF) 567:frame 555:Gecko 550:after 517:Opera 479:NATed 414:Some 270:email 193:Types 181:and 164:Flash 68:OWASP 2142:Time 2132:Fork 1926:2015 1906:2015 1886:2015 1861:2018 1836:2018 1811:(5), 1793:2019 1768:2024 1742:2019 1716:2019 1691:2019 1666:2019 1641:2009 1620:2008 1593:2008 1567:2008 1551:and 1547:2008 1525:2008 1498:2008 1476:2008 1463:ISBN 1441:2008 1418:2008 1392:2008 1363:2008 1340:2019 1315:2019 1290:2019 1265:2010 1235:2016 1153:2008 1141:and 1137:2008 1109:2008 1096:ISBN 1075:2008 1011:ISBN 981:2008 946:2008 923:2008 897:2010 871:2008 846:2023 824:2014 803:2003 776:2024 705:w3af 541:Ajax 539:and 436:very 324:AJAX 303:worm 282:they 260:(or 256:The 228:(or 224:The 201:and 168:HTML 156:Java 112:(3) 86:and 2147:Zip 1944:XSS 1333:npm 1044:doi 1007:128 965:CSO 628:by 332:DOM 286:her 212:DOM 146:or 110:and 31:XSS 2558:: 1950:, 1946:, 1942:: 1916:. 1896:. 1852:. 1827:. 1784:. 1759:. 1732:. 1707:. 1682:. 1657:. 1610:. 1557:. 1371:^ 1331:. 1306:. 1281:. 1243:^ 1225:. 1056:^ 1040:58 1038:. 1034:. 1009:. 989:^ 967:. 963:. 914:. 888:. 848:. 792:. 759:. 632:. 489:. 459:. 355:. 326:. 305:. 174:. 162:, 158:, 154:, 131:. 108:, 64:. 1985:e 1978:t 1971:v 1928:. 1908:. 1888:. 1863:. 1838:. 1795:. 1770:. 1744:. 1718:. 1693:. 1668:. 1643:. 1622:. 1595:. 1569:. 1549:. 1527:. 1500:. 1478:. 1443:. 1420:. 1394:. 1365:. 1342:. 1317:. 1292:. 1267:. 1237:. 1155:. 1139:. 1111:. 1077:. 1050:. 1046:: 1019:. 983:. 948:. 925:. 899:. 873:. 826:. 805:. 778:. 29:( 23:.

Index

XSS (disambiguation)
vulnerability
web applications
inject
client-side scripts
access controls
same-origin policy
Symantec
network
OWASP
misnomer
Web security
Same-origin policy
same-origin policy
URI scheme
host name
port number
web-based applications
servers
code injection
Microsoft
security context
ActiveX
Java
VBScript
Flash
HTML
information security
Twitter
Facebook

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