CVE-2016-5312 in Messaging Gateway
Summary
by MITRE
Directory traversal vulnerability in the charting component in Symantec Messaging Gateway before 10.6.2 allows remote authenticated users to read arbitrary files via a .. (dot dot) in the sn parameter to brightmail/servlet/com.ve.kavachart.servlet.ChartStream.
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Analysis
by VulDB Data Team • 06/30/2024
The vulnerability identified as CVE-2016-5312 represents a critical directory traversal flaw within Symantec Messaging Gateway's charting component, specifically affecting versions prior to 10.6.2. This issue resides in the brightmail servlet implementation at the path brightmail/servlet/com.ve.kavachart.servlet.ChartStream where the sn parameter fails to properly validate user input. The vulnerability enables authenticated remote attackers to access arbitrary files on the underlying file system by exploiting insufficient input sanitization mechanisms. The flaw manifests when the application processes the sn parameter without adequate filtering to prevent path traversal sequences, allowing malicious actors to navigate beyond the intended directory structure and retrieve sensitive files from the server.
The technical implementation of this vulnerability stems from improper input validation within the charting servlet component, which directly incorporates user-supplied data into file system operations without sufficient sanitization. When an attacker submits a crafted sn parameter containing directory traversal sequences such as .. or similar path manipulation constructs, the application processes these inputs without proper boundary checks, resulting in unauthorized file access. This vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw operates at the application layer and demonstrates a classic weakness in input validation where user-controllable parameters are directly used in file system operations without proper security controls.
The operational impact of CVE-2016-5312 extends beyond simple information disclosure, as authenticated attackers can potentially access sensitive configuration files, log data, system credentials, or other confidential information stored on the messaging gateway server. This vulnerability compromises the confidentiality of the system and can lead to further exploitation opportunities, including potential privilege escalation or lateral movement within the network. The authenticated nature of the attack means that an attacker must first obtain valid credentials, but this requirement does not significantly reduce the risk given that many organizations maintain default or weak credentials that can be easily compromised through various attack vectors. The vulnerability also aligns with ATT&CK technique T1083, which covers the discovery of system information through directory listing and file access, potentially enabling more sophisticated attacks.
Organizations affected by this vulnerability should immediately implement the vendor-provided patch or upgrade to Symantec Messaging Gateway version 10.6.2 or later, which addresses the directory traversal flaw through proper input validation mechanisms. System administrators should also implement network segmentation and access controls to limit the exposure of the affected servlet to only authorized users. Additional mitigations include monitoring for suspicious directory traversal patterns in web application logs, implementing web application firewalls with content filtering capabilities, and conducting comprehensive security assessments of the messaging infrastructure. The vulnerability demonstrates the importance of input validation in preventing path traversal attacks and highlights the need for regular security updates and vulnerability management processes. Organizations should also consider implementing principle of least privilege access controls for administrative functions and regularly review authentication mechanisms to prevent unauthorized access to critical system components.