Weakness (CWE)
CWE-79: Cross-site Scripting
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
How to prevent it (8 mitigations)
-
Architecture and Design
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
-
Implementation, Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies.
For any data that will be output to another web page, especially any data that was received from external inputs, use the appropriate encoding on all non-alphanumeric characters.
Parts of the same output document may require different encodings, which will vary depending on whether the output is in the:
- HTML body
- Element attributes (such as src="XYZ")
- URIs
- JavaScript sections
- Cascading Style Sheets and style property
etc. Note that HTML Entity Encoding is only appropriate for the HTML body.
Consult the XSS Prevention Cheat Sheet [REF-724] for more details on the types of encoding and escaping that are needed.
-
Architecture and Design, Implementation
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
-
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
-
Architecture and Design
If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.
-
Implementation
Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.
The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.
-
Implementation
With Struts, write all data from form beans with the bean's filter attribute set to true.
-
Implementation
To help mitigate XSS attacks against the user's session cookie, set the session cookie to be HttpOnly. In browsers that support the HttpOnly feature (such as more recent versions of Internet Explorer and Firefox), this attribute can prevent the user's session cookie from being accessible to malicious client-side scripts that use document.cookie. This is not a complete solution, since HttpOnly is not supported by all browsers. More importantly, XmlHttpRequest and other powerful browser technologies provide read access to HTTP headers, including the Set-Cookie header in which the HttpOnly flag is set.
Source: MITRE CWE-79
32,780 results · Feed
-
Medium 6.8
WP Highlight Box <= 1.0 - Contributor+ Stored XSS via highlight-box Shortcode
The WP Highlight Box WordPress plugin through 1.0 does not escape some shortcode attributes before outputting them in a page where the shortcode is embedded, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting at…
-
Medium 6.8
Masteriyo LMS < 3.4.1 - Instructor+ Stored XSS via Course Highlights
The Masteriyo LMS WordPress plugin before 3.4.1 does not sanitise and escape one of its course fields before outputting it back in the course editor, allowing users with the instructor role to perform Stored Cross-Site Scripting attacks against higher privile…
-
High 7.1
Export & Import WPBakery Page Builder <= 1.0.2 - Stored XSS via CSRF
The Export & Import WPBakery Page Builder WordPress plugin through 1.0.2 does not perform any CSRF check on its template-import feature and does not sanitise the imported data before storing it and echoing it back, allowing attackers to make a logged-in admin…
-
High 8.8
BE REST Endpoints <= 1.0.0 - Unauthenticated Stored XSS and Widget Manipulation
The BE REST Endpoints WordPress plugin through 1.0.0 does not perform any authorization check before allowing widgets to be read, created, updated and deleted, and does not sanitize the values it stores in them, allowing unauthenticated users to inject arbitr…
-
Medium 6.8
Custom Menu Wizard <= 3.3.1 - Contributor+ Stored XSS via Shortcode Attributes
The Custom Menu Wizard Widget WordPress plugin through 3.3.1 does not sanitize and escape several shortcode attributes before rendering them into HTML, allowing users with contributor-level access and above to inject arbitrary web scripts that execute when th…
-
Medium 5.4
QloApps through 1.7.0 Reflected XSS via List Filter Parameters
QloApps through 1.7.0 renders back-office list filter POST parameters into HTML input value attributes without escaping them in the list helper template. Attackers can induce authenticated users to submit crafted POST requests with malicious payloads to list …
-
Medium 5.4
Cross-site Scripting in Malcolm
A web interface reflects a portion of the request URL into a script context and a hyperlink attribute without adequate encoding, and does not require authentication to reach. This allows an unauthenticated network attacker to craft a link that, when visited b…
-
Medium 6.4
Stored DOM-XSS in public shared-folder image gallery (one-click, unauthenticated victim)
Dobase is an open-source, self-hosted workspace with installable tools. Versions prior to 2026.06.03 have a one-click stored DOM-based cross-site scripting (XSS) vulnerability in the public, unauthenticated shared-folder image gallery. A file's `name` is full…
-
Medium 4.8
Concrete CMS below 9.5.3 is vulnerable to Stored XSS via the Date Format field in the Page Attribute Display block
Concrete CMS below 9.5.3 is vulnerable to Stored XSS via the Date Format field in the Page Attribute Display block. A user with edit_page_contents permissions could store a payload which executes in the browser of any visitor who viewed a page where the block…
-
Medium 5.1
Concrete CMS below 9.5.3 is vulnerable to Stored XSS in the Document Library block file description and tags
Concrete CMS below 9.5.3 does not apply HTML output escaping to the file description and tags fields when rendering the Document Library block, so a user with permission to edit file properties could store a script payload that executed in the browser of any …
-
Medium 6.1
Microsoft Edge (Chromium-based) Spoofing Vulnerability
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Edge (Chromium-based) allows an unauthorized attacker to perform spoofing over a network.
-
Medium 5.8
Concrete CMS versions 9.0.0 to 9.5.2 is vulnerable to Stored XSS in Board Custom Slot save_template via Unescaped Summary Description
Concrete CMS versions 9.0.0 to 9.5.2 is vulnerable to Stored XSS in Board Custom Slot dialog. The custom_slot save_template endpoint authorizes the request only against the target board instance (canEditBoardContents()) and then persists the client-supplied s…
-
Medium 6.5
WordPress Visual Composer Website Builder plugin <= 45.16.1 - Cross Site Scripting (XSS) vulnerability
Contributor Cross Site Scripting (XSS) in Visual Composer Website Builder <= 45.16.1 versions.
-
Medium 6.5
WordPress Simple Payment plugin <= 2.5.4 - Cross Site Scripting (XSS) vulnerability
Contributor Cross Site Scripting (XSS) in Simple Payment <= 2.5.4 versions.
-
Medium 6.5
WordPress Bold Page Builder plugin <= 5.9.9 - Cross Site Scripting (XSS) vulnerability
Contributor Cross Site Scripting (XSS) in Bold Page Builder <= 5.9.9 versions.
-
Medium 6.0
Concrete CMS 9.5.2 and below is vulnerable to Stored XSS in RSS Displayer Block via Unescaped Remote Feed Item title
Concrete CMS RSS Displayer block below version 9.5.3 rendered remote feed item titles without HTML escaping, resulting in stored cross-site scripting. An attacker able to control a title in a syndicated feed could execute script in the site origin for any vis…
-
Medium 6.1
Reflected XSS in IdeaSoft's Smart E-Commerce
Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in IdeaSoft Software Industry and Trade Inc. Smart E-Commerce allows Reflected XSS. This issue affects Smart E-Commerce: before 8.4.2.0.
-
Medium 6.1
Chamilo LMS Stored XSS via Survey Answer Submission in reporting.php
Chamilo LMS before 1.11.42 and 3.0.0 contains a stored cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious script payloads into survey answers by computing deterministic invitation codes and bypassing authorization che…
-
High 8.7
AVideo LoginControl Stored XSS via PGP Public Key
AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the LoginControl plugin that fails to HTML-encode PGP public keys echoed into a textarea element. An authenticated attacker can inject malic…
-
High 8.7
AVideo Bookmark Plugin Stored XSS via Chapter Names
AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the Bookmark plugin where chapter names are not encoded before being concatenated into public watch-page HTML. A video owner can inject mali…
-
High 8.7
AVideo CustomizeUser Stored XSS via field_name Parameter
AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the CustomizeUser plugin where the field_name parameter is stored raw without sanitization. Administrators can inject malicious scripts via …
-
High 8.7
AVideo Stored XSS via donationLink in watch page button
WWBN AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the user 'donationLink' profile field. User::setDonationLink() (objects/user.php) stores the value and save() validates it only with fi…
-
High 8.7
AVideo YPTWallet Stored XSS via CryptoWallet Configuration
AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in the YPTWallet plugin where user-supplied CryptoWallet values are base64-encoded but not HTML-escaped before storage in wallet_log.informatio…
-
Medium 6.1
WWBN AVideo Reflected XSS via Gallery Category getBackURL
WWBN AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a reflected cross-site scripting vulnerability in plugin/Gallery/view/Category.php when SubCategorys is enabled. The getBackURL parameter is echoed into an href attribute without HTM…
-
High 8.1
WWBN AVideo Stored XSS via UserGroups setGroup_name
WWBN AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a stored cross-site scripting vulnerability in UserGroups::setGroup_name() that fails to sanitize group_name input. Administrators with canAdminUserGroups permission can inject malic…
-
Medium 6.1
WWBN AVideo Reflected XSS via confirmLivePassword.php
WWBN AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a reflected cross-site scripting vulnerability in confirmLivePassword.php that copies REQUEST_URI into a form action attribute without encoding. Attackers can craft a malicious URL w…
-
Medium 6.1
WWBN AVideo Reflected XSS via confirmLivePassword.php
WWBN AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a reflected cross-site scripting vulnerability in plugin/Live/confirmLivePassword.php. The script interpolates the unauthenticated GET parameter u (which is not covered by $securityF…
-
Medium 6.1
WWBN AVideo Reflected XSS via Referer Header Comment Breakout
WWBN AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 contains a reflected cross-site scripting vulnerability in the showAlertMessage() function that inserts the raw Referer header into a JavaScript comment without encoding. Attackers can craft …
-
High 7.2
Kirki <= 6.2.0 - Unauthenticated Stored Cross-Site Scripting via 'comment' Parameter
The Kirki – Freeform Page Builder, Website Builder & Customizer plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘comment’ parameter in all versions up to, and including, 6.2.0 due to insufficient input sanitization and output escapin…
-
Medium 6.4
Media Library Assistant <= 3.35 - Authenticated (Author+) Stored Cross-Site Scripting via Bulk Edit Preset Export/Import
The Media Library Assistant plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the bulk edit preset export/import mechanism in versions up to and including 3.35. This is due to insufficient output escaping on preset field values when they a…
-
Medium 6.4
Media Library Assistant <= 3.35 - Authenticated (Contributor+) Stored Cross-Site Scripting via mla_link_attributes Parameter
The Media Library Assistant plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'mla_link_attributes' parameter in all versions up to, and including, 3.35 due to insufficient input sanitization and output escaping. This makes it possible…
-
Medium 6.4
Media Library Assistant <= 3.35 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'mla_link_href' Shortcode Parameter
The Media Library Assistant plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'mla_gallery' shortcode in versions up to and including 3.35. This is due to insufficient input sanitization and output escaping on the mla_link_href paramet…
-
Medium 6.8
AI Builder 2.4.1 - 2.7.7 - Contributor+ Stored XSS via Post JavaScript
The AI Builder WordPress plugin before 2.7.8 does not sanitise custom JavaScript saved against a post before echoing it inside a script tag on the front end, allowing users with contributor level access and above to store arbitrary JavaScript that will execut…
-
High 8.8
Gutenverse News < 3.3.3 - Unauthenticated Stored XSS via Comment Content
The Gutenverse News WordPress plugin before 3.3.3 does not restrict the extra HTML it adds to WordPress's allowed elements to the context it is meant for, applying the same relaxed list to every sanitisation context including untrusted comments, allowing unau…
-
Medium 6.8
Featured Image with URL < 1.0.6 - Contributor+ Stored XSS via Image Alt Text
The Featured Image with URL WordPress plugin before 1.0.6 does not sanitise and escape a stored image attribute value before outputting it, which could allow users with a role as low as Contributor to perform Stored Cross-Site Scripting attacks that execute i…
-
Medium 5.4
Advanced Customized Prompts <= 1.0.1 - Subscriber+ Stored XSS via Product Popup Configuration
The advanced-customized-prompts WordPress plugin through 1.0.1 does not perform any capability, ownership, or nonce check before saving popup configuration to a product, nor escape the stored values on output, allowing any authenticated user such as a subscri…
-
Low 3.5
GTranslate < 3.0.10 - Admin+ Stored XSS
The Translate WordPress with GTranslate WordPress plugin before 3.0.10 does not validate one of its settings before the bundled front-end scripts build markup from it, allowing users with a role as high as administrator to store JavaScript that runs in the se…
-
Medium 6.8
CoolClock < 4.3.8 - Contributor+ Stored XSS via Skin Class Attribute
The CoolClock WordPress plugin before 4.3.8 does not properly escape a skin setting before outputting it within an HTML attribute, allowing users with contributor-level access and above to inject arbitrary web scripts that execute when the content is viewed.
-
Medium 6.8
CoolClock < 4.3.8 - Contributor+ Stored XSS via Custom Skin JSON
The CoolClock WordPress plugin before 4.3.8 does not properly escape a custom skin setting before outputting it inside an inline script, allowing users with contributor-level access and above to inject arbitrary JavaScript that executes when the content is vi…
-
Medium 6.1
Themify – WooCommerce Product Filter <= 1.5.5 - Reflected Cross-Site Scripting
The Themify – WooCommerce Product Filter plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via Query Parameter Name in all versions up to, and including, 1.5.5 due to insufficient input sanitization and output escaping. This makes it possib…