CVE-2014-2324 in lighttpd
Summary
by MITRE
Multiple directory traversal vulnerabilities in (1) mod_evhost and (2) mod_simple_vhost in lighttpd before 1.4.35 allow remote attackers to read arbitrary files via a .. (dot dot) in the host name, related to request_check_hostname.
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Analysis
by VulDB Data Team • 05/08/2026
The vulnerability identified as CVE-2014-2324 represents a critical directory traversal flaw affecting lighttpd web servers running versions prior to 1.4.35. This issue manifests in two distinct modules within the lighttpd configuration: mod_evhost and mod_simple_vhost, both of which handle virtual host configurations and are susceptible to malicious host name manipulation. The vulnerability stems from inadequate input validation in the request_check_hostname function, which processes host header values during HTTP request processing. Attackers can exploit this weakness by crafting specially formatted host names containing .. (dot dot) sequences that should be properly sanitized but are instead processed as directory navigation commands.
The technical exploitation of CVE-2014-2324 occurs when an attacker submits a malicious host header value that includes directory traversal sequences such as ../../etc/passwd or ../../../windows/system32/drivers/etc/hosts. The vulnerable lighttpd modules fail to properly sanitize these inputs before using them to construct file paths for virtual host resolution. This flaw allows attackers to bypass normal file system access controls and retrieve arbitrary files from the server's file system. The vulnerability is particularly dangerous because it operates at the HTTP request level and does not require authentication, making it accessible to any remote attacker with network connectivity to the affected server.
From an operational impact perspective, this vulnerability exposes organizations to significant data compromise risks including exposure of sensitive configuration files, authentication credentials, system user databases, and application source code. The attack surface is broad as it affects both mod_evhost and mod_simple_vhost modules, which are commonly deployed in production environments for managing virtual hosts and domain routing. Security professionals should note that this vulnerability aligns with CWE-22 Directory Traversal and can be mapped to ATT&CK technique T1083 File and Directory Discovery, as attackers can systematically enumerate and extract files from the compromised system. The vulnerability's impact is amplified by the fact that it affects core web server functionality rather than application-specific code paths.
Organizations should immediately implement mitigations including upgrading to lighttpd version 1.4.35 or later, which contains the necessary patches to sanitize host header inputs properly. Additional defensive measures include implementing host header validation rules at the network perimeter, configuring web application firewalls to detect and block suspicious host header patterns, and restricting access to the web server through network segmentation. Security monitoring should include detection of host header patterns containing .. sequences or other traversal indicators. The vulnerability demonstrates the importance of proper input validation in web server configurations and highlights how seemingly benign configuration modules can become attack vectors when inadequate sanitization is implemented. Organizations should also review their virtual host configurations to ensure that all modules handling user-provided data are properly secured against path traversal attacks.