CVE-2004-0175 in OpenSSH
Summary
by MITRE
Directory traversal vulnerability in scp for OpenSSH before 3.4p1 allows remote malicious servers to overwrite arbitrary files. NOTE: this may be a rediscovery of CVE-2000-0992.
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Analysis
by VulDB Data Team • 05/26/2019
The vulnerability described in CVE-2004-0175 represents a critical directory traversal flaw within the secure copy protocol implementation of OpenSSH versions prior to 3.4p1. This security weakness specifically affects the scp command functionality that enables secure file transfers between hosts, creating a scenario where remote attackers can manipulate file operations to overwrite arbitrary files on the target system. The vulnerability stems from insufficient input validation and path resolution mechanisms within the scp client implementation, allowing malicious servers to exploit improper handling of file paths during copy operations.
The technical nature of this flaw aligns with CWE-22, which categorizes directory traversal vulnerabilities as weaknesses that occur when applications fail to properly validate or sanitize input paths. When a user connects to a malicious scp server, the vulnerable client processes file paths without adequate safeguards against directory traversal sequences such as ../ or ..\ that could allow access to parent directories. The scp protocol typically operates over ssh connections and relies on the secure shell for authentication, but the vulnerability exists specifically within the file transfer component rather than the authentication layer. This creates a scenario where even authenticated connections can be exploited to manipulate file system operations beyond the intended scope of the transfer.
The operational impact of this vulnerability extends beyond simple file overwrites to potentially compromise entire system configurations and sensitive data repositories. Attackers could leverage this weakness to overwrite critical system files, configuration scripts, or user data files, potentially leading to system instability, data loss, or privilege escalation. The vulnerability particularly affects systems where users might connect to untrusted scp servers or where scp is used in automated environments without proper input validation. Organizations relying on scp for file transfers across networks face significant risk as the malicious server can exploit this flaw to overwrite files in any location where the scp client has write permissions.
Security mitigations for this vulnerability primarily involve upgrading to OpenSSH version 3.4p1 or later, which contains the necessary patches to address the directory traversal issue. System administrators should also implement network segmentation and access controls to limit exposure to untrusted scp servers, while monitoring for suspicious file operations that might indicate exploitation attempts. The vulnerability demonstrates the importance of input validation in network protocols and highlights how even secure communication channels can be compromised through flaws in file handling operations. Organizations should also consider implementing additional controls such as file integrity monitoring and regular security audits to detect potential exploitation attempts. This vulnerability serves as a reminder of the critical need for comprehensive security testing of network protocols, particularly those handling file operations, and underscores the importance of maintaining current security patches across all system components.