Home Plans Products
Tools
Technology Trends Keyword Lists Browser Extensions
Features
Lead Generation Market Analysis Sales Intelligence
Resources
FAQ About Contact Blog
Account
Login Sign up
Home / Blog / Apache 2.4.34
Security Advisory

Apache 2.4.34: 4 CVEs Found - Security Update Guide

📅 June 07, 2026 ·⏱ 5 min read ·🔒 SiteRecipe Security Team
508 websites still running Apache 2.4.34  → View full list
4
Total
2
High
2
Medium

Apache HTTP Server 2.4.34 contains 4 known vulnerabilities that could put your website at risk. Two of these are classified as HIGH severity, including critical flaws in HTTP/2 request handling that could lead to complete server denial of service. With over 500 websites still running this outdated version, understanding these risks is essential for maintaining a secure online presence.

This comprehensive guide walks you through identifying if your server is vulnerable, understanding what each CVE means, and implementing the necessary fixes. Whether you're a website owner or IT professional, protecting your infrastructure from these known exploits should be your immediate priority.

What is Apache 2.4.34?

Apache HTTP Server 2.4.34 is a web server software that powers millions of websites worldwide. Released in 2018, this version was meant to improve performance and add new features. However, security researchers later discovered multiple vulnerabilities that could allow attackers to crash or disable your website without proper authorization. Think of it like a lock on a door—this version has some broken locks that need fixing.

Web servers like Apache are the backbone of the internet, serving web pages and content to visitors. When vulnerabilities exist in these servers, they become targets for cybercriminals who can exploit them to disrupt service, steal data, or gain unauthorized access. Running outdated server software is like leaving your front door unlocked—it's an open invitation for trouble.

Key Vulnerabilities in Apache 2.4.34

4 CVEs found. The most critical are explained below.

HIGH CVE-2018-1333 7.5/10 · CVSS v3.0 ⏱ Immediate
HTTP/2 Request Causes Server Overload

Attackers can send specially crafted HTTP/2 requests that trick your server into holding onto worker processes far longer than needed. This exhausts your server's capacity to handle legitimate customer requests, causing your website to become unavailable.

Impact: Your website could go offline or become extremely slow, preventing customers from accessing it. This is a denial of service attack that requires you to restart your server to recover.

↗ View on NVD
HIGH CVE-2018-8011 7.5/10 · CVSS v3.0 ⏱ Immediate
Certificate Management Feature Crashes Server

If you use Apache's automatic certificate management feature (mod_md), attackers can send malformed requests that cause the server process to crash. Your website would go down until the server restarts.

Impact: Your website experiences unexpected downtime as server processes crash. Attackers can repeatedly trigger this to keep your site offline.

↗ View on NVD
MEDIUM CVE-2018-11763 5.9/10 · CVSS v3.0 ⏱ Within 7 days
HTTP/2 Connections Consume Server Resources

Attackers can open HTTP/2 connections and send large data packets repeatedly, tying up your server's processing power and connections without triggering any timeout. This slowly starves your server of resources.

Impact: Your website becomes slow and unresponsive for legitimate users as server resources get consumed by the attack. The server stays up but functions poorly.

↗ View on NVD
MEDIUM CVE-2019-0197 4.2/10 · CVSS v3.1 ⏱ Immediate
HTTP Upgrade Request Causes Server Crash

If certain HTTP/2 settings are enabled, attackers can send upgrade requests that confuse your server's configuration and cause it to crash. This only affects the newer 2.4.34+ versions with specific HTTP/2 settings.

Impact: Your server crashes and becomes unavailable. Attackers can use this to trigger repeated outages with specially timed requests.

↗ View on NVD

Is your website running Apache 2.4.34?

Scan your site in 30 seconds. Used by 500+ web agencies.

How to Check If Your Website Is Affected

How to Fix These Vulnerabilities

Conclusion

Apache 2.4.34 is no longer safe for production environments. The two HIGH severity vulnerabilities can be exploited to crash your server, disrupting service for your customers and damaging your reputation. With security updates readily available, there's no reason to delay upgrading to a patched version. Don't become another statistic—take action today to protect your digital assets.

SiteRecipe.com specializes in identifying and remedying security vulnerabilities in web server configurations. Our automated scanning tool detects outdated software, misconfigurations, and known CVEs across your entire infrastructure in minutes. Start your free security assessment today and get peace of mind knowing your Apache servers are protected against these critical threats.

Frequently Asked Questions

What exactly is CVE-2018-1333 and how does it affect me?
CVE-2018-1333 is a HIGH severity vulnerability that allows attackers to send specially crafted HTTP/2 requests that cause Apache to waste server resources for 60 seconds longer than necessary. By sending many such requests, attackers can exhaust all available worker processes, causing your website to become completely unavailable (denial of service). This vulnerability affects Apache versions 2.4.18 through 2.4.30 and 2.4.33.
Do I need to upgrade immediately or can I wait?
You should upgrade immediately. These vulnerabilities are publicly documented and well-known to hackers. The longer you wait, the higher the risk of your website being targeted. The upgrade process typically takes 15-30 minutes and causes minimal disruption if done during off-peak hours. Waiting increases your exposure to attacks exponentially.
What happens if my website gets attacked through these CVEs?
Attackers can crash your website by sending malicious HTTP/2 requests, causing complete downtime and loss of revenue. In some cases, they could also trigger segmentation faults in Apache processes. The impact ranges from hours of lost service to potential data exposure, depending on how quickly you respond to the attack and restore service.
Will upgrading Apache break my website?
Upgrading from 2.4.34 to newer versions (2.4.41+) is generally safe and maintains backward compatibility. Most websites experience zero downtime if you follow proper backup procedures before upgrading. We recommend testing the upgrade on a staging environment first if you have complex configurations.
How can I verify my website is secure after upgrading?
After upgrading, run 'apache2 -v' to confirm the new version, then restart Apache and monitor access logs for errors. SiteRecipe.com also offers free post-upgrade scanning to verify all known CVEs have been patched and your configuration is secure.

Generate white-label reports for your clients

Web agencies use SiteRecipe to produce branded PDF security reports in 30 seconds.

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.

Source: nvd.nist.gov · Published: June 07, 2026 · SiteRecipe.com