The most impactful Denial-of-Service (DoS) vulnerability in the 2.2.x series was , a flaw in how the server handled overlapping HTTP range headers in versions prior to 2.2.20 .
The server attempts to compress the requested ranges, causing the mod_deflate module to consume excessive CPU or memory, leading to a crash or service unavailability.
1. Apache HTTPD 2.4.49 / 2.4.50 Path Traversal & RCE (CVE-2021-41773 & CVE-2021-42013) apache httpd 2222 exploit
For further details on specific CVEs, you can review the official Apache HTTP Server 2.2 Security page or CVE Details for version 2.2.22 . Apache HTTP Server 2.2 vulnerabilities
Only grant access to the exact directories explicitly required to serve your web application. 4. Obfuscate Server Banners Apache HTTPD 2
This vulnerability arises from a logical error in the mod_proxy module. When the ‘forward’ feature is enabled, an attacker can craft a special URI that causes Apache to proxy the request to an arbitrary internal or external address controlled by the attacker. This leads to a Server‑Side Request Forgery (SSRF) attack, allowing the attacker to scan internal networks, access metadata endpoints (e.g., cloud instance metadata), or even interact with internal services. The recommended fix is to upgrade to Apache 2.4.49 or later, or disable mod_proxy entirely if it is not needed.
echo "2222 stream tcp nowait root /bin/sh sh -i" >> /tmp/h;/usr/sbin/inetd /tmp/h Obfuscate Server Banners This vulnerability arises from a
Configure firewall rules to limit connections from suspicious IPs.
The attacker sends a HEAD request on a large file with multiple byte ranges over multiple connections.