CVE-2015-6659 in Drupal
Summary
by MITRE
SQL injection vulnerability in the SQL comment filtering system in the Database API in Drupal 7.x before 7.39 allows remote attackers to execute arbitrary SQL commands via an SQL comment.
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Analysis
by VulDB Data Team • 06/13/2022
The CVE-2015-6659 vulnerability represents a critical SQL injection flaw within the Drupal content management system that specifically targets the Database API's SQL comment filtering mechanism. This vulnerability affects all Drupal 7.x installations prior to version 7.39 and enables remote attackers to execute arbitrary SQL commands through carefully crafted SQL comments. The flaw resides in how the system processes and filters SQL comments during database query operations, creating an exploitable condition that bypasses normal input validation measures.
The technical implementation of this vulnerability stems from inadequate sanitization of SQL comments within the Database API layer of Drupal 7.x. When the system encounters SQL comments in user-supplied input, the filtering mechanism fails to properly escape or remove these comments before they are processed by the database engine. This oversight allows attackers to inject malicious SQL code that gets executed with the privileges of the database user account. The vulnerability specifically exploits the way Drupal handles comment characters within SQL queries, enabling attackers to manipulate database operations through indirect injection vectors.
From an operational perspective, this vulnerability poses significant risks to Drupal-based web applications as it allows remote code execution without requiring authentication or specific user privileges. Attackers can leverage this flaw to extract sensitive data, modify database contents, delete information, or even escalate their access to gain administrative control over the affected systems. The impact extends beyond simple data theft, as successful exploitation can lead to complete system compromise and potential lateral movement within network environments where Drupal systems are deployed. Organizations running vulnerable Drupal installations face substantial risk of data breaches and service disruption.
The vulnerability aligns with CWE-89 which specifically addresses SQL injection flaws in software applications, and maps to ATT&CK technique T1190 for exploiting vulnerabilities in web applications. The attack surface is particularly concerning given Drupal's widespread adoption across various industries including government, healthcare, and financial services. Mitigation strategies include immediate patching to Drupal 7.39 or later versions, implementing proper input validation and sanitization measures, and deploying web application firewalls to monitor and block suspicious SQL comment patterns. Additionally, organizations should conduct comprehensive vulnerability assessments to identify other potential injection points within their Drupal installations and implement database access controls to limit the impact of successful exploitation attempts.