CVE-2011-2891 in Joomla
Summary
by MITRE
Joomla! 1.6.x before 1.6.2 allows remote attackers to obtain sensitive information via an empty Itemid array parameter to index.php, which reveals the installation path in an error message, a different vulnerability than CVE-2011-2488.
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Analysis
by VulDB Data Team • 04/21/2019
The vulnerability identified as CVE-2011-2891 affects Joomla instance. The flaw demonstrates characteristics consistent with CWE-200, which catalogs weaknesses related to improper information exposure, and aligns with ATT&CK technique T1212 for data manipulation and information gathering activities. The vulnerability operates through a simple parameter manipulation attack vector where an attacker can craft malicious requests to probe the system's configuration and directory structure.
The technical implementation of this vulnerability exploits the lack of proper input validation within Joomla installation resides. The error occurs because the system attempts to access array elements that do not exist, triggering an unhandled exception that displays the installation directory in the error output. This behavior represents a classic case of insecure error handling where system internals are exposed to unauthorized users, enabling attackers to gather reconnaissance information that could facilitate subsequent attacks.
The operational impact of CVE-2011-2891 extends beyond simple information disclosure, as it provides attackers with critical system reconnaissance data that can be leveraged for more sophisticated attacks. The exposed installation paths enable attackers to understand the server configuration, potentially revealing whether the system uses specific directory structures, file permissions, or deployment patterns that might be exploited in conjunction with other vulnerabilities. This information disclosure vulnerability can be particularly dangerous when combined with other reconnaissance techniques, as it provides attackers with precise knowledge of the target environment that can be used to tailor more effective exploitation strategies. The vulnerability affects all Joomla! 1.6.x installations before version 1.6.2, making it a widespread concern for organizations running these older versions.
Mitigation strategies for CVE-2011-2891 focus primarily on applying the official security patch released by Joomla! for version 1.6.2, which addresses the input validation issue by properly handling empty Itemid parameters. System administrators should also implement proper error handling configurations that suppress detailed error messages in production environments, following security best practices outlined in OWASP guidelines for web application security. The vulnerability demonstrates the importance of input validation and proper error handling in web applications, with recommendations aligning with ATT&CK tactic TA0011 for privilege escalation and TA0007 for discovery activities. Organizations should also consider implementing web application firewalls that can detect and block suspicious parameter patterns, and conduct regular security audits to ensure that error handling configurations are properly implemented across all web applications in their environment.