CVE-2014-5019 in Drupal
Summary
by MITRE
The multisite feature in Drupal 6.x before 6.32 and 7.x before 7.29 allows remote attackers to cause a denial of service via a crafted HTTP Host header, related to determining which configuration file to use.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 03/26/2022
The vulnerability identified as CVE-2014-5019 represents a critical denial of service weakness within Drupal's multisite implementation that affected versions prior to 6.32 and 7.29. This flaw specifically targets the way Drupal processes HTTP Host headers to determine which configuration file should be loaded for multisite environments. The issue arises from insufficient validation of the Host header parameter, which allows malicious actors to manipulate the system's configuration loading mechanism through carefully crafted requests.
The technical exploitation of this vulnerability occurs when an attacker sends a specially crafted HTTP Host header that contains directory traversal sequences or other malformed input patterns. Drupal's multisite system uses the Host header to determine which site configuration to load from the sites directory structure, where each site typically has its own configuration file. When the system fails to properly sanitize or validate this input, it can lead to unexpected behavior in the configuration file resolution process. This weakness falls under the category of improper input validation as defined by CWE-20, specifically involving the handling of HTTP headers in web applications.
The operational impact of this vulnerability extends beyond simple service disruption to potentially enable more sophisticated attacks within the affected environment. Remote attackers can leverage this flaw to exhaust system resources through repeated requests that cause the application to process invalid configuration paths or attempt to load non-existent files. This resource exhaustion can manifest as memory leaks, CPU overutilization, or even complete application unresponsiveness, effectively creating a denial of service condition that impacts legitimate users and services. The vulnerability is particularly dangerous in multi-tenant environments where multiple sites share the same Drupal installation, as it could potentially affect the entire platform rather than just individual sites.
Organizations affected by this vulnerability should prioritize immediate patching of their Drupal installations to versions 6.32 and 7.29 or later, which contain the necessary fixes for proper Host header validation. Additionally, implementing network-level mitigations such as HTTP header filtering and rate limiting can provide additional protection while patches are deployed. Security monitoring should include detection of suspicious Host header patterns and unusual request volumes that might indicate exploitation attempts. The ATT&CK framework categorizes this vulnerability under the T1499.004 technique for network denial of service, while the CWE classification of 20 indicates the fundamental flaw in input validation that enables the exploitation. Organizations should also review their multisite configuration practices and ensure that proper access controls are in place to limit the impact of potential exploitation attempts.