CVE-2018-0646 in Explzh
Summary
by MITRE
Directory traversal vulnerability in Explzh v.7.58 and earlier allows an attacker to read arbitrary files via unspecified vectors.
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Analysis
by VulDB Data Team • 03/20/2020
The CVE-2018-0646 vulnerability represents a directory traversal flaw in Explzh version 7.58 and earlier, which constitutes a critical security weakness in archive handling software. This vulnerability falls under the category of path traversal attacks that exploit insufficient input validation mechanisms within file system operations. The flaw enables attackers to access files outside the intended directory structure through manipulation of file path references, potentially leading to unauthorized data exposure and system compromise. The vulnerability is particularly concerning because it affects a widely used archiving utility that processes compressed files and handles various file operations. The unspecified vectors mentioned in the description suggest that the attack could be triggered through multiple pathways within the application's file processing logic, making it challenging to predict or fully mitigate all potential attack surfaces. This type of vulnerability commonly occurs when applications fail to properly sanitize user-supplied input before using it in file system operations, creating opportunities for malicious actors to navigate beyond designated directories.
The technical implementation of this directory traversal vulnerability stems from inadequate validation of file paths within the Explzh application's archive processing routines. When the software handles compressed files containing specially crafted path references, it fails to properly filter or sanitize these paths before executing file system operations. This allows attackers to include sequences such as "../" or similar path manipulation patterns that cause the application to traverse directories beyond its intended scope. The vulnerability is classified as a CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which is a well-documented weakness in software security practices. Attackers can exploit this by creating malicious archive files that contain path traversal sequences within their file entries, enabling them to read arbitrary files from the system. The specific vectors for exploitation likely involve manipulating file names or directory structures within archive files, potentially leveraging the application's handling of symbolic links or absolute path references. This weakness essentially allows an attacker to bypass normal file access controls and retrieve sensitive information that should remain protected.
The operational impact of CVE-2018-0646 extends beyond simple unauthorized file access, potentially enabling more severe consequences within compromised systems. An attacker could leverage this vulnerability to access configuration files, user credentials, system logs, or other sensitive data stored on the target system. The vulnerability may also facilitate further exploitation attempts by providing access to system binaries or libraries that could be used to escalate privileges or deploy additional malware. In environments where Explzh is used for processing untrusted archive files, this vulnerability creates a persistent attack surface that could be exploited by adversaries to gain unauthorized access to network resources or sensitive corporate data. The impact is particularly significant in enterprise environments where archive processing is automated or used in critical workflows, as it could lead to data breaches or system compromise without proper detection. The vulnerability could also be chained with other exploits to create more sophisticated attack vectors, potentially allowing attackers to execute arbitrary code on the target system.
Mitigation strategies for CVE-2018-0646 should focus on immediate patching and implementation of defensive measures to protect against directory traversal attacks. The primary solution involves updating to Explzh version 7.59 or later, which contains the necessary fixes for the path traversal vulnerability. Organizations should implement comprehensive input validation and sanitization measures to prevent malicious path sequences from being processed by the application. This includes implementing strict path validation that rejects any input containing directory traversal sequences or absolute path references. Security controls should also include restricting file system access permissions for the Explzh application, limiting its ability to access sensitive directories even if exploitation occurs. Network-based protections such as intrusion detection systems and web application firewalls can help detect and block suspicious file processing activities that may indicate exploitation attempts. Additionally, organizations should implement principle of least privilege concepts for archive processing applications, ensuring they operate with minimal necessary permissions and access rights. The vulnerability highlights the importance of proper input validation and the need for security reviews of file handling operations, particularly in applications that process untrusted data from external sources. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other applications and systems within the organization's infrastructure.