A critical security vulnerability has been discovered in LiteSpeed Technologies LiteSpeed Cache software that affects its versions n/a through 5.7. This vulnerability is assigned the CVE identifier CVE-2023-40000 and is explained in detail below. Improper neutralization of input during the web page generation process results in a cross-site scripting (XSS) vulnerability that allows attackers to inject their own malicious scripts into web pages created by the LiteSpeed Cache plugin. This can lead to a wide range of consequences, such as stealing user data and web session cookies, defacement of websites, and other serious repercussions.

Exploit Details

LiteSpeed Cache is a popular caching plugin for websites using LiteSpeed server technologies, responsible for improving performance and reducing server load. However, inadequate input sanitization in various parts of the codebase exposes the plugin to stored XSS attacks.

The vulnerability is primarily introduced due to improper implementation of input sanitization in the LiteSpeed Cache plugin, which does not filter out malicious scripts before storing the content. An attacker with the ability to post content could, therefore, execute arbitrary JavaScript code by injecting it into their posts. When a victim visits the compromised page, the malicious script is executed in their browser, potentially leading to compromised accounts, leaked personal information, and other attacks.

Here's a code snippet showcasing the vulnerable part of the plugin

# Vulnerable code snippet in LiteSpeed Cache plugin
function litespeed_store_post($content) {
  // Insufficient input sanitization
  $sanitized_content = strip_tags($content);

  // Store the content
  set_cache($sanitized_content);

  return $content;
}

Original References

- CVE-2023-40000 - National Vulnerability Database (NVD)
- LiteSpeed Technologies LiteSpeed Cache Security Advisory

Mitigations

In order to mitigate this vulnerability, users are advised to update LiteSpeed Cache to the latest version, which includes patches to address this vulnerability. You can check for the latest version on the LiteSpeed Cache GitHub repository.

Additionally, website owners can implement Content Security Policies (CSP) on their web applications to restrict the execution of JavaScript and other potentially harmful content. By setting a strong and restrictive CSP, attackers would have a harder time exploiting this vulnerability even if they could inject malicious content.

Here's an example of a strong CSP header

Content-Security-Policy: default-src 'self'; script-src 'self'; object-src 'none'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; media-src 'self'; frame-src 'none'; font-src 'self'; connect-src 'self'

Conclusion

In conclusion, CVE-2023-40000 demonstrates the importance of proper input sanitization and handling during web page generation. LiteSpeed Cache users are encouraged to update their software promptly to prevent any potential exploitation of this vulnerability. By keeping the software up-to-date and using a comprehensive security approach, including Content Security Policies, web developers can minimize the risk posed by these and other vulnerabilities.

Timeline

Published on: 04/16/2024 18:15:10 UTC