CVE-2005-1229 in cpio
Summary
by MITRE
Directory traversal vulnerability in cpio 2.6 and earlier allows remote attackers to write to arbitrary directories via a .. (dot dot) in a cpio file.
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Analysis
by VulDB Data Team • 08/01/2019
The directory traversal vulnerability in cpio version 2.6 and earlier represents a critical security flaw that enables remote attackers to manipulate file system operations through maliciously crafted cpio archives. This vulnerability specifically exploits the improper handling of directory traversal sequences within cpio file extraction processes, allowing adversaries to write files to arbitrary locations on the target system. The flaw exists in the archive extraction mechanism where the software fails to adequately sanitize or validate path components during file restoration, creating opportunities for privilege escalation and unauthorized file system modifications.
This vulnerability operates at the core of archive handling functionality within Unix-like operating systems, where cpio serves as a fundamental tool for creating and extracting archive files. The technical implementation flaw stems from insufficient input validation of file paths contained within cpio archives, particularly when processing directory entries that contain ".." sequences. When cpio encounters such traversal sequences, it fails to properly restrict the extraction process to the intended target directory, instead allowing the extraction to proceed beyond the designated boundaries. This behavior creates a path traversal condition that can be exploited to overwrite critical system files, create unauthorized directories, or place malicious payloads in privileged locations.
The operational impact of this vulnerability extends beyond simple file system manipulation, as it can lead to complete system compromise when combined with other attack vectors. Remote attackers can leverage this flaw to execute arbitrary code by placing malicious binaries in system directories or overwrite critical configuration files that control system behavior. The vulnerability affects systems that rely on cpio for package installation, system updates, or backup restoration processes, making it particularly dangerous in enterprise environments where automated deployment scripts might process untrusted archive files. According to CWE-22, this represents a classic path traversal vulnerability that allows attackers to access files and directories outside the intended scope, while the ATT&CK framework categorizes this under privilege escalation techniques through file system manipulation.
Mitigation strategies for this vulnerability require immediate patching of cpio installations to versions that properly sanitize path components during extraction operations. System administrators should implement strict file access controls and limit the execution of cpio commands with elevated privileges to reduce the potential impact of exploitation. Additional protective measures include implementing proper input validation for all archive files before processing, using sandboxed environments for archive extraction, and monitoring file system modifications for suspicious patterns. Organizations should also consider implementing network segmentation and access controls to limit exposure of systems that process untrusted cpio archives. The remediation process must include thorough testing of patched versions to ensure that legitimate archive operations continue to function properly while eliminating the directory traversal capabilities that enable exploitation.