CVE-2018-7706 in SecurMail
Summary
by MITRE
Directory traversal vulnerability in SecurEnvoy SecurMail before 9.2.501 allows remote authenticated users to read arbitrary e-mail messages via a .. (dot dot) in the option2 parameter in an attachment action to secmail/getmessage.exe.
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Analysis
by VulDB Data Team • 06/29/2024
The vulnerability identified as CVE-2018-7706 represents a critical directory traversal flaw within SecurEnvoy SecurMail version 9.2.400 and earlier, which exposes organizations to potential unauthorized access to sensitive email communications. This issue specifically affects the attachment handling functionality of the email system, where the application fails to properly validate user input before processing file paths. The vulnerability resides in the secmail/getmessage.exe component which processes the option2 parameter, allowing malicious actors to manipulate file access through directory traversal sequences. Security researchers have classified this as a directory traversal vulnerability, which maps to CWE-22 in the Common Weakness Enumeration catalog, specifically addressing improper limitation of a pathname to a restricted directory. The flaw enables attackers to bypass normal access controls and retrieve arbitrary email messages stored on the server by exploiting the .. (dot dot) traversal sequence in the parameter. This vulnerability is particularly dangerous because it requires only authenticated access to the email system, meaning that an attacker who has obtained legitimate credentials can exploit this weakness without requiring additional privileges or system-level access. The impact extends beyond simple information disclosure, as email messages may contain sensitive corporate data, personal information, or confidential communications that could be leveraged for further attacks or breaches. The attack vector involves sending specially crafted requests to the vulnerable endpoint with maliciously constructed option2 parameters that traverse the file system to access files outside of the intended directory structure. According to ATT&CK framework, this vulnerability aligns with T1005 (Data from Local System) and T1078 (Valid Accounts) as it exploits legitimate user accounts to access unauthorized data. Organizations using SecurEnvoy SecurMail are particularly at risk since the vulnerability allows for arbitrary file reading, potentially enabling attackers to access not just email content but also underlying system files or other sensitive data stored within the application's directory structure. The flaw demonstrates a fundamental lack of input validation and proper path sanitization in the application's file handling mechanisms, which represents a common pattern in web application security vulnerabilities. The severity of this vulnerability is compounded by the fact that it can be exploited remotely, meaning that attackers do not need physical access to the system or network infrastructure to carry out the attack. The affected version range indicates that organizations running SecurEnvoy SecurMail versions prior to 9.2.501 are vulnerable, and the patch release 9.2.501 specifically addresses this directory traversal issue. Organizations should immediately implement the vendor-provided security update to remediate this vulnerability and prevent potential exploitation by threat actors who may be actively targeting this specific weakness in email infrastructure systems. The vulnerability serves as a reminder of the critical importance of proper input validation and secure coding practices in preventing directory traversal attacks that can lead to significant data breaches and unauthorized access to sensitive communications.
The technical exploitation of CVE-2018-7706 requires an authenticated user session within the SecurEnvoy SecurMail system, which significantly reduces the attack surface compared to vulnerabilities requiring no authentication. However, this also means that the vulnerability can be particularly dangerous when users are compromised through phishing attacks or credential theft, as attackers can immediately leverage the authenticated session to exploit the directory traversal flaw. The vulnerability specifically targets the attachment handling functionality where the application processes the option2 parameter without proper sanitization, allowing attackers to manipulate the file path to access files outside the intended directory scope. This type of vulnerability is classified as a path traversal attack under the CWE-22 category, which encompasses various forms of improper input validation that allow attackers to access files or directories they should not be able to reach. The exploitation process involves crafting malicious requests to the secmail/getmessage.exe endpoint with specially formatted option2 parameters that contain directory traversal sequences, effectively allowing attackers to browse the file system and retrieve unauthorized content. The impact of this vulnerability extends beyond simple file access, as it can potentially expose sensitive system files, configuration data, or other files that may contain credentials or other information useful for further attacks. Organizations should implement network segmentation and access controls to limit the impact of such vulnerabilities, ensuring that even if an attacker gains access to one system, they cannot easily move laterally to access other critical systems. The vulnerability also highlights the importance of proper security testing and code review processes, as directory traversal issues are among the most commonly exploited weaknesses in web applications according to various security research organizations and vulnerability databases. Security professionals should also consider implementing web application firewalls or other protective measures that can detect and block suspicious path traversal patterns in real-time, providing additional defense in depth against this specific class of attack. The vulnerability's classification under ATT&CK framework as a data access and credential exploitation vector emphasizes the need for comprehensive monitoring and detection capabilities to identify when such attacks are being attempted against email infrastructure systems. Organizations should also conduct regular vulnerability assessments and penetration testing to identify similar weaknesses in their email systems and other critical infrastructure components that may be susceptible to similar directory traversal attacks.