Nginx 1.4.6 contains a critical security vulnerability that affects thousands of websites worldwide. CVE-2016-1247 is a HIGH severity issue that could allow attackers to gain unauthorized access to your server through privilege escalation. If you're running this outdated version, your website and user data may be at serious risk.
This vulnerability impacts Debian and Ubuntu systems running vulnerable Nginx packages, with 1,487 websites still using the affected version. The good news is that the fix is straightforward and can be implemented quickly. Our comprehensive guide will walk you through identifying the vulnerability and securing your server.
Don't let your website become a target. Understanding this vulnerability and taking immediate action is essential for maintaining your cybersecurity posture and protecting your users' trust.
What is Nginx 1.4.6?
Nginx is a high-performance web server and reverse proxy used by millions of websites to serve content efficiently and manage traffic. Think of it as a sophisticated traffic director for your website—it receives visitor requests and routes them to the appropriate destination on your server. Nginx 1.4.6 is an older version released years ago that powers many established websites, though newer versions are now widely available with enhanced security features.
While Nginx is generally considered lightweight and secure, like all software, older versions can contain vulnerabilities that cybercriminals exploit. CVE-2016-1247 is a privilege escalation flaw discovered in Nginx 1.4.6 that allows attackers to escalate their permissions on your server. This means an attacker with limited access could potentially gain full control, compromising your entire website and any data it contains.
Key Vulnerabilities in Nginx 1.4.6
1 CVEs found. The most critical are explained below.
HIGHCVE-2016-12477.8/10 · CVSS v3.1
⏱ Immediate
Local User Privilege Escalation in Nginx
A vulnerability in Nginx versions 1.4.6 and earlier allows people who have access to your server's system to gain higher-level permissions than they should have. This is a serious security flaw because it lets attackers escalate their privileges and potentially take control of your entire web server.
Impact: An attacker with basic server access could gain root-level control of your Nginx server, allowing them to modify your website, steal data, install malware, or take your site offline completely.
1Connect to your server via SSH and log in with administrator privileges
2Run the command 'nginx -v' to display your current Nginx version number
3Compare the output with 1.4.6—if it matches, your server is vulnerable to CVE-2016-1247
4Document your findings and note the exact version and your operating system distribution
How to Fix These Vulnerabilities
1Back up your entire Nginx configuration directory by running 'sudo cp -r /etc/nginx /etc/nginx.backup' to preserve your current settings
2Update your system packages with 'sudo apt-get update' followed by 'sudo apt-get upgrade nginx' on Ubuntu/Debian systems
3Verify the upgrade was successful by running 'nginx -v' and confirming the version number has increased beyond 1.4.6
4Restart Nginx with 'sudo systemctl restart nginx' and monitor your website logs for any errors or warnings over the next 24 hours
Conclusion
Addressing CVE-2016-1247 in Nginx 1.4.6 is not optional—it's a critical security requirement for protecting your website and users. The vulnerability has been public since 2016, making it a prime target for automated attacks and malicious actors. By upgrading to a patched version, you eliminate this attack vector and significantly improve your overall server security posture. The process takes just minutes but provides years of protection.
SiteRecipe.com provides continuous vulnerability scanning and security monitoring to identify risks like CVE-2016-1247 before they become critical problems. Our platform scans thousands of websites and provides actionable intelligence about software vulnerabilities, outdated packages, and misconfigurations. Use SiteRecipe.com today to discover vulnerabilities on your website, get prioritized remediation recommendations, and maintain a strong security foundation for your digital presence.
Frequently Asked Questions
How serious is CVE-2016-1247 really?
CVE-2016-1247 is rated HIGH severity because it enables privilege escalation—allowing attackers to move from limited access to full administrative control. This is extremely dangerous because it could result in complete server compromise, data theft, and website defacement. Immediate patching is essential.
Will upgrading Nginx break my website?
Upgrading Nginx is generally safe and maintains backward compatibility with most configurations. However, it's always wise to back up your configuration files (as shown in our guide) and test on a staging environment first. Most websites experience zero downtime during the upgrade process.
Why is Nginx 1.4.6 still being used if it's vulnerable?
Many websites run outdated Nginx versions due to stability preferences, minimal maintenance resources, or lack of awareness about vulnerabilities. Legacy systems often remain unchanged unless problems arise. However, security should drive these decisions—staying current with security patches is essential.
Can attackers exploit this vulnerability remotely?
CVE-2016-1247 typically requires some form of local or application-level access to exploit, but combined with other vulnerabilities, it can be part of a complete attack chain. The risk increases significantly if your website has other security issues that attackers could leverage first.
How often should I check for vulnerabilities like this?
Ideally, you should scan for vulnerabilities continuously or at minimum monthly. SiteRecipe.com provides automated ongoing scanning so you're never surprised by newly discovered vulnerabilities affecting your infrastructure. Regular monitoring is the best defense against emerging security threats.
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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.