CVE-2008-6171 in Drupal
Summary
by MITRE
includes/bootstrap.inc in Drupal 5.x before 5.12 and 6.x before 6.6, when the server is configured for "IP-based virtual hosts," allows remote attackers to include and execute arbitrary files via the HTTP Host header.
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Analysis
by VulDB Data Team • 10/28/2018
The vulnerability described in CVE-2008-6171 represents a critical remote code execution flaw affecting Drupal content management systems versions 5.x prior to 5.12 and 6.x prior to 6.6. This issue specifically exploits the way Drupal handles HTTP Host headers when servers are configured with IP-based virtual hosting, creating a path for attackers to manipulate the application's include mechanism and execute malicious code remotely. The flaw exists in the includes/bootstrap.inc file which serves as the core initialization component of Drupal's bootstrapping process, making it a fundamental entry point for exploitation.
The technical mechanism behind this vulnerability involves the improper sanitization and validation of HTTP Host header values within the Drupal framework. When a server operates with IP-based virtual hosting, Drupal's bootstrap process relies on the Host header to determine which configuration files to include and load. Attackers can manipulate this header to point to malicious file paths, bypassing normal access controls and file inclusion restrictions. This creates a classic path traversal and remote file inclusion scenario where the application's own include functionality becomes a vector for arbitrary code execution. The vulnerability directly maps to CWE-94, which describes "Improper Control of Generation of Code ('Code Injection')" and specifically addresses weaknesses in the validation of input parameters used in dynamic code execution contexts.
The operational impact of this vulnerability extends beyond simple code execution to encompass complete system compromise when exploited successfully. An attacker can leverage this flaw to upload and execute malicious scripts, potentially gaining full administrative control over the Drupal installation. The implications are particularly severe in multi-tenant hosting environments where IP-based virtual hosting is common, as it allows attackers to target specific sites within a shared infrastructure. This vulnerability affects the core application functionality and can lead to data breaches, service disruption, and unauthorized access to sensitive information stored within the Drupal database. The attack surface is broad since many web servers use IP-based virtual hosting configurations, making this a widespread concern for Drupal deployments.
Mitigation strategies for CVE-2008-6171 primarily involve applying the official security patches released by the Drupal project, specifically upgrading to versions 5.12 or 6.6 and later. Organizations should also implement network-level restrictions such as firewall rules that limit access to the Host header manipulation, though this approach is less robust than proper patching. Security monitoring should be enhanced to detect unusual Host header patterns in web server logs, as this vulnerability often manifests through crafted HTTP requests. The remediation process should include thorough testing of patched versions to ensure no regression in functionality, particularly regarding virtual hosting configurations. Additionally, implementing proper input validation and sanitization practices at the application level can provide defense-in-depth against similar vulnerabilities, aligning with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: PowerShell" and broader defensive strategies outlined in the MITRE ATT&CK framework for web application attacks.