CVE-2015-1386 in unshield
Summary
by MITRE
Directory traversal vulnerability in unshield 1.0-1.
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Analysis
by VulDB Data Team • 11/10/2019
The directory traversal vulnerability identified as CVE-2015-1386 affects the unshield package version 1.0-1, which is commonly used for extracting files from InstallShield self-extracting archives. This vulnerability represents a critical security flaw that allows attackers to manipulate file paths during the extraction process, potentially leading to arbitrary file write operations. The issue stems from insufficient input validation within the file path handling mechanisms of the unshield utility, creating opportunities for malicious actors to exploit the software's extraction routines.
The technical implementation of this vulnerability resides in the improper handling of directory traversal sequences such as ../ or ..\ within file paths during archive extraction. When unshield processes archive files, it fails to adequately sanitize or validate the paths specified in the archive metadata, allowing attackers to specify arbitrary file paths that can overwrite critical system files or create malicious files in unintended locations. This flaw operates at the file system level and can be exploited through carefully crafted archive contents that contain malicious path sequences designed to traverse directories beyond the intended extraction target.
The operational impact of CVE-2015-1386 extends beyond simple file corruption, as it can enable attackers to execute arbitrary code on affected systems. An attacker who can influence the contents of an InstallShield archive or gain access to a system where unshield is used for extraction can leverage this vulnerability to place malicious files in system directories, potentially leading to privilege escalation or persistent backdoor installation. The vulnerability is particularly concerning in environments where unshield is used to process untrusted archive files from external sources, as it creates a direct path for remote code execution through the extraction process itself.
Security professionals should recognize this vulnerability as mapping to CWE-22, which specifically addresses directory traversal or path traversal flaws in software implementations. The attack vector aligns with techniques documented in the ATT&CK framework under T1059 for command and script injection, as successful exploitation may enable attackers to execute malicious code through the compromised extraction process. Organizations should implement immediate mitigations including updating to patched versions of unshield, implementing strict file validation policies for archive processing, and monitoring for unauthorized file modifications in system directories. The vulnerability underscores the importance of input validation and proper path handling in file processing utilities, particularly those operating in environments where they may encounter untrusted data sources.
The broader implications of this vulnerability highlight the critical need for robust security practices in software that handles file extraction and archive processing. Legacy software packages often contain such vulnerabilities due to insufficient security review processes during their development lifecycle, making them prime targets for exploitation. System administrators should prioritize patch management for all software components that handle file extraction, particularly those used in automated processing environments or systems that process external archives. The vulnerability also demonstrates how seemingly benign file processing utilities can become attack vectors when proper security controls are not implemented in their design and deployment.