CVE-2020-25136 in Professional
Summary
by MITRE
An issue was discovered in Observium Professional, Enterprise & Community 20.8.10631. It is vulnerable to directory traversal and local file inclusion due to the fact that there is an unrestricted possibility of loading any file with an inc.php extension. Inclusion of other files (even though limited to the mentioned extension) can lead to Remote Code Execution. This can occur via /device/device=345/?tab=routing&proto=../ URIs to device/routing.inc.php.
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Analysis
by VulDB Data Team • 09/25/2020
This vulnerability exists in Observium Professional, Enterprise, and Community versions up to 20.8.10631 where improper input validation allows attackers to exploit directory traversal and local file inclusion flaws. The core issue stems from the application's failure to properly sanitize user-supplied URI parameters, specifically within the device routing functionality. When an attacker crafts a malicious URI such as /device/device=345/?tab=routing&proto=../ the system processes these parameters without adequate restrictions, enabling arbitrary file access patterns. The vulnerability is particularly dangerous because it allows loading any file with an inc.php extension, which creates a pathway for remote code execution through the inclusion of malicious files. The technical flaw resides in the lack of proper path validation and sanitization mechanisms within the application's input handling routines, which directly maps to CWE-22 - Improper Limitation of a Pathname to a Restricted Directory. This weakness allows attackers to traverse the filesystem and include arbitrary files, potentially leading to complete system compromise.
The operational impact of this vulnerability is severe as it provides attackers with a direct path to execute arbitrary code on the affected system. The vulnerability can be exploited through simple HTTP requests without requiring authentication, making it particularly dangerous in environments where the application is accessible from untrusted networks. Attackers can leverage this flaw to upload and execute malicious PHP code, potentially gaining shell access to the server, extracting sensitive data, or establishing persistent backdoors. The vulnerability affects the core device monitoring functionality of Observium, which is typically used for network infrastructure monitoring, meaning that successful exploitation could provide attackers with access to critical network information and potentially compromise the entire network monitoring infrastructure. This aligns with ATT&CK technique T1059.007 - Command and Scripting Interpreter: PowerShell, as attackers can execute arbitrary commands through the included PHP files, and T1083 - File and Directory Discovery, since the traversal capabilities allow for comprehensive filesystem exploration.
Mitigation strategies should focus on implementing proper input validation and sanitization measures across all user-supplied parameters. Organizations should immediately apply the vendor-provided patches or upgrades to eliminate this vulnerability. The recommended approach involves implementing strict whitelisting of allowed values for URI parameters, particularly those related to file inclusion operations. Security controls should include proper path validation that prevents directory traversal sequences such as '../' or '..\\' from being processed. Additionally, implementing the principle of least privilege for file inclusion operations and restricting the ability to include files based on extension alone would significantly reduce the attack surface. Network segmentation and access controls should be implemented to limit exposure of the Observium application to untrusted networks. Organizations should also consider deploying web application firewalls to detect and block malicious requests attempting to exploit this vulnerability. Regular security assessments and input validation testing should be conducted to ensure that similar vulnerabilities are not present in other parts of the application or related systems. The fix should align with security best practices outlined in the OWASP Top Ten and should include comprehensive logging of file access attempts to aid in incident response and forensic analysis.