CVE-2021-3293 in emlog
Summary
by MITRE • 02/09/2021
emlog v5.3.1 has full path disclosure vulnerability in t/index.php, which allows an attacker to see the path to the webroot/file.
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Analysis
by VulDB Data Team • 02/25/2021
The vulnerability identified as CVE-2021-3293 affects emlog version 5.3.1 and represents a full path disclosure flaw located in the t/index.php file. This type of vulnerability exposes sensitive system information including the absolute path to the webroot directory and specific file locations on the server. The flaw occurs when the application fails to properly sanitize error messages or when it inadvertently reveals internal system paths during error processing, allowing unauthorized users to gain knowledge of the server's file structure and potentially sensitive directory locations.
This vulnerability falls under CWE-209, which specifically addresses the disclosure of error information that could aid attackers in understanding the system architecture. The technical implementation of this flaw involves the application's error handling mechanisms in the t/index.php script, where uncontrolled error messages or stack traces may be displayed to end users. When an error occurs within this particular file, the system reveals the complete file path, including the webroot directory structure, which provides attackers with crucial information for planning further attacks.
The operational impact of this vulnerability is significant as it enables attackers to map the server's file system structure, which can facilitate more sophisticated attacks such as local file inclusion exploits, directory traversal attempts, or targeted attacks against specific files within the application's directory structure. The disclosed paths may reveal sensitive information about the server configuration, including the exact location of the web application, which could be leveraged to bypass security controls or to craft more effective attack vectors. This information disclosure represents a foundational weakness that can enable attackers to better understand the target environment and plan subsequent exploitation phases.
Security practitioners should implement multiple layers of mitigation for this vulnerability. The primary fix involves updating emlog to a patched version that properly handles error messages and prevents path disclosure in error conditions. Additionally, server configurations should be adjusted to suppress detailed error messages from being displayed to end users, implementing proper error handling that logs errors internally while presenting generic error messages to users. The ATT&CK framework categorizes this type of vulnerability under T1068, which involves the exploitation of remote services, and T1082, which covers system information discovery, making it a critical target for defensive measures. Organizations should also consider implementing web application firewalls that can detect and block requests attempting to trigger path disclosure vulnerabilities, along with regular security scanning to identify similar issues across their web applications.