CVE-2016-10399 in Sendio
Summary
by MITRE
Sendio versions before 8.2.1 were affected by a Local File Inclusion vulnerability that allowed an unauthenticated, remote attacker to read potentially sensitive system files via a specially crafted URL.
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Analysis
by VulDB Data Team • 11/01/2019
The vulnerability identified as CVE-2016-10399 represents a critical local file inclusion flaw in Sendio email security appliances that affected versions prior to 8.2.1. This vulnerability resides within the web application interface of the Sendio platform, which serves as a comprehensive email security solution designed to protect organizations from various email-based threats including spam, malware, and phishing attacks. The flaw stems from inadequate input validation and sanitization within the application's URL handling mechanisms, creating a pathway for malicious actors to manipulate file access requests through crafted web requests.
The technical implementation of this vulnerability allows an attacker to exploit the application's failure to properly validate and sanitize user-supplied input parameters. Specifically, when the web application processes incoming requests containing file path parameters, it fails to adequately filter or escape special characters that could be used to traverse the file system hierarchy. This weakness enables an attacker to craft malicious URLs that include directory traversal sequences such as ../ or ..\ which can navigate beyond the intended application directories and access arbitrary files on the underlying operating system. The vulnerability is particularly dangerous because it operates without requiring authentication, making it accessible to any remote user who can reach the affected web interface.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to access sensitive system files that could contain critical organizational data, configuration information, or authentication credentials. Attackers could potentially access system logs, configuration files containing database connection strings, user account information, or other sensitive data that would normally be protected within the application's security boundaries. The unauthenticated nature of the attack means that organizations with exposed Sendio appliances could be compromised without any prior access credentials or insider knowledge, making this vulnerability particularly attractive to automated scanning and exploitation campaigns. This flaw effectively undermines the security posture of affected organizations by allowing unauthorized access to potentially sensitive data through a publicly accessible web interface.
Organizations affected by this vulnerability should immediately implement the remediation measures provided by Sendio in their 8.2.1 release, which typically includes enhanced input validation, proper parameter sanitization, and implementation of secure file access controls. The mitigation strategy should also incorporate network segmentation to limit access to the Sendio appliance, implementation of web application firewalls to detect and block malicious requests, and regular security assessments to identify similar vulnerabilities in other applications. From a cybersecurity framework perspective, this vulnerability aligns with CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, and maps to ATT&CK technique T1083 - File and Directory Discovery, highlighting the need for comprehensive security controls that address both the immediate vulnerability and broader reconnaissance capabilities that attackers may leverage. The incident underscores the critical importance of maintaining up-to-date security patches and implementing robust input validation controls across all web applications to prevent similar path traversal vulnerabilities from compromising system integrity.