CVE-2015-9277 in MailEnable
Summary
by MITRE
MailEnable before 8.60 allows Directory Traversal for reading the messages of other users, uploading files, and deleting files because "/../" and "/.. /" are mishandled.
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Analysis
by VulDB Data Team • 05/02/2020
The vulnerability identified as CVE-2015-9277 affects MailEnable versions prior to 8.60 and represents a critical directory traversal flaw that enables unauthorized access to user mailboxes and system resources. This weakness stems from improper handling of directory traversal sequences in the application's file system operations, specifically when processing paths containing "/../" and "/.. /" sequences. The vulnerability exists at the core of MailEnable's message handling and file management functions, where input validation fails to properly sanitize user-supplied paths before they are processed by the underlying file system operations.
The technical implementation of this flaw allows an attacker to manipulate file paths through crafted requests that exploit the application's failure to properly resolve directory traversal sequences. When the application encounters these malformed path sequences, it fails to properly validate or canonicalize the paths, enabling attackers to navigate outside the intended directory boundaries and access files that should be restricted. This vulnerability specifically impacts the application's ability to properly handle path resolution, creating a condition where legitimate file access controls are bypassed through manipulation of the path traversal sequences. The flaw operates at the operating system level where file system calls are made, making it particularly dangerous as it can be exploited to read arbitrary files, upload malicious content, and delete critical system files.
The operational impact of this vulnerability is severe and multifaceted, as it provides attackers with the ability to perform unauthorized actions across multiple user accounts and system resources. An attacker can read messages from other users' mailboxes, effectively compromising email privacy and potentially accessing sensitive business communications, personal information, or confidential data. The vulnerability also enables file upload capabilities that can be used to deploy malicious payloads, establish persistence mechanisms, or escalate privileges within the system. Additionally, the ability to delete files creates potential for data destruction or system disruption, making this a particularly dangerous vulnerability for email server environments. This weakness directly violates the principle of least privilege and allows for unauthorized access that could lead to complete system compromise.
Security practitioners should implement immediate mitigations including upgrading to MailEnable version 8.60 or later, which contains proper input validation and path canonicalization fixes. Network segmentation and access controls should be implemented to limit exposure of the mail server to untrusted networks, while monitoring should be enabled to detect suspicious file access patterns and path traversal attempts. Regular security assessments should be conducted to identify similar vulnerabilities in other applications, as this type of flaw often indicates broader input validation issues within the application architecture. The vulnerability aligns with CWE-22 Directory Traversal and maps to ATT&CK technique T1078 Valid Accounts for privilege escalation, as it allows attackers to access resources beyond their intended scope. Organizations should also consider implementing web application firewalls and input sanitization measures to prevent similar path traversal attacks across their infrastructure.