PHP 5.6.38 contains a medium-severity security vulnerability that could expose your website to cross-site scripting (XSS) attacks. CVE-2018-17082 affects the way PHP handles certain types of web requests, potentially allowing attackers to inject malicious code into your site. With 919 websites still running this vulnerable version, understanding and addressing this flaw is crucial for maintaining robust security. This guide walks you through identifying the vulnerability and implementing the necessary fixes to protect your digital assets.
What is Php 5.6.38?
PHP 5.6.38 is a server-side programming language used to build and manage websites. It processes requests from visitors' browsers and generates the web pages you see online. Think of PHP as the engine that powers your website's functionality—handling everything from user logins to form submissions. PHP versions are numbered, and 5.6.38 was released as a maintenance update to patch security issues in the older PHP 5.6 series.
Like all software, PHP occasionally discovers security weaknesses that need fixing. CVE-2018-17082 is one such weakness found in PHP 5.6.38 and several other versions. This particular flaw relates to how the Apache web server (which works alongside PHP) handles special types of web requests called "chunked" transfers. When not handled correctly, this can create an opening for attackers to inject harmful scripts into your website.
Key Vulnerabilities in Php 5.6.38
1 CVEs found. The most critical are explained below.
Your PHP 5.6.38 website has a security weakness that lets attackers inject harmful code through specially crafted requests. This code can then run on your visitors' browsers without your knowledge. The problem exists in how your server handles certain types of data transfers.
Impact: Attackers could steal visitor information, redirect users to fake websites, inject malware, or damage your website's reputation. Your customers' data and trust are at risk.
1Log into your web hosting control panel (cPanel, Plesk, etc.) and navigate to the PHP version or software section
2Look for your current PHP version number—if it displays 5.6.38 or another 5.6.x version, your site may be vulnerable
3Alternatively, create a simple PHP file containing <?php phpinfo(); ?> in your root directory, visit it in your browser, and check the version displayed
How to Fix These Vulnerabilities
1Back up your entire website and database immediately—this is your safety net before making changes
2Log into your hosting control panel and locate the PHP version selector or upgrade option
3Update PHP to version 5.6.39 or higher (preferably 7.4+ for better security and performance), ensuring your website code is compatible first
4Test your website thoroughly after upgrading to confirm all features work correctly, then delete any temporary PHP info files you created
Conclusion
CVE-2018-17082 represents a genuine security risk for the 919 websites still running PHP 5.6.38. XSS vulnerabilities can lead to compromised user data, stolen credentials, and damaged website reputation. Taking action now prevents costly security breaches later and demonstrates commitment to protecting your visitors' information.
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Frequently Asked Questions
What exactly is an XSS vulnerability and how could it harm my site?
XSS (Cross-Site Scripting) allows attackers to inject malicious JavaScript code into your website. When visitors load your site, this code runs in their browsers, potentially stealing login credentials, session cookies, or sensitive information. It can also deface your site or redirect users to malicious websites, severely damaging your reputation and visitor trust.
Will upgrading PHP break my website?
Most websites upgrade without issues, but older custom code might need adjustments. Before upgrading, test in a staging environment to ensure compatibility. Contact your developer if you use custom plugins or scripts. Modern hosting providers often provide one-click upgrade options with automatic rollback if problems occur.
Why is PHP 5.6 still being used if it's vulnerable?
Many websites use PHP 5.6 due to legacy code, custom applications, or hosting limitations. Some developers delay upgrades due to costs or compatibility concerns. However, staying on vulnerable versions poses serious security risks that far outweigh upgrade inconveniences. Modern PHP versions offer better security, speed, and support.
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DISCLAIMER: This report is based on publicly available CVE data from the National Vulnerability
Database (NVD) maintained by NIST. Detection of a technology version does not confirm active
exploitation on any specific website. For informational purposes only.
SiteRecipe is not responsible for actions taken based on this report.
Always consult a qualified security professional.