CVE-2012-4554 in Drupal
Summary
by MITRE
The OpenID module in Drupal 7.x before 7.16 allows remote OpenID servers to read arbitrary files via a crafted DOCTYPE declaration in an XRDS file.
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Analysis
by VulDB Data Team • 12/19/2021
The vulnerability identified as CVE-2012-4554 represents a critical security flaw within the OpenID module of Drupal 7.x versions prior to 7.16. This issue stems from insufficient input validation and sanitization mechanisms within the module's processing of XRDS (XRDS Descriptor) files, which are used to establish OpenID identity verification protocols. The vulnerability specifically targets the handling of DOCTYPE declarations within these XML-based descriptor files, creating a path for remote attackers to exploit a weakness in the XML parsing mechanism.
The technical exploitation of this vulnerability occurs through a maliciously crafted DOCTYPE declaration within an XRDS file that is processed by the vulnerable Drupal installation. When the OpenID module encounters such a declaration, it fails to properly sanitize or validate the XML entities, allowing an attacker-controlled remote OpenID server to manipulate the XML parsing behavior. This flaw enables attackers to construct specific DOCTYPE declarations that can cause the XML parser to attempt reading arbitrary files from the server's filesystem, potentially exposing sensitive information such as configuration files, database credentials, or other system resources.
The operational impact of CVE-2012-4554 extends beyond simple information disclosure, as it provides attackers with the ability to access files that may contain critical system information or credentials. The vulnerability operates at the XML parsing layer, making it particularly dangerous because it can be exploited through legitimate OpenID authentication flows without requiring special privileges or direct system access. This characteristic places the vulnerability within the ATT&CK framework's initial access category, specifically under techniques involving credential access and privilege escalation through legitimate system access.
The flaw aligns with CWE-20, which describes improper input validation in software systems, and CWE-94, which addresses the execution of arbitrary code through code injection vulnerabilities. The vulnerability's exploitation path demonstrates how XML external entity processing can be abused to create a server-side request forgery or file inclusion attack vector. Organizations running affected Drupal installations face significant risk, as the vulnerability can be exploited through any legitimate OpenID authentication attempt, making it particularly insidious for security monitoring and detection.
Mitigation strategies for this vulnerability require immediate patching of affected Drupal installations to version 7.16 or later, which includes proper input sanitization for XML processing. Additionally, organizations should implement network-level controls to restrict access to OpenID services and consider disabling OpenID authentication where possible. Security monitoring should focus on detecting unusual XML processing activities and unauthorized file access patterns. The vulnerability also highlights the importance of validating external XML content and implementing proper XML parser configurations that disable external entity processing, aligning with industry best practices for secure XML handling as recommended by the OWASP XML Security guidelines and the NIST Cybersecurity Framework.