CVE-2015-8228 in Huawei
Summary
by MITRE
Directory traversal vulnerability in the SFTP server in Huawei AR 120, 150, 160, 200, 500, 1200, 2200, 3200, and 3600 routers with software before V200R006SPH003 allows remote authenticated users to access arbitrary directories via unspecified vectors.
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Analysis
by VulDB Data Team • 04/18/2018
The CVE-2015-8228 vulnerability represents a critical directory traversal flaw within the SFTP server implementation of Huawei AR series routers. This vulnerability affects multiple models including the AR 120, 150, 160, 200, 500, 1200, 2200, 3200, and 3600 device families operating with firmware versions prior to V200R006SPH003. The flaw enables remote authenticated attackers to bypass normal file system access controls and gain unauthorized access to arbitrary directories on the affected devices. This represents a significant security risk as it allows attackers who have already established authentication credentials to escalate their privileges and access sensitive system files, configuration data, and potentially other network resources that should be restricted.
The technical nature of this vulnerability stems from inadequate input validation within the SFTP server component of the Huawei routers. When processing file system operations through SFTP, the server fails to properly sanitize user-supplied paths, allowing attackers to manipulate directory traversal sequences such as ../ or ..\ to navigate outside the intended directory boundaries. This flaw falls under the Common Weakness Enumeration category CWE-22, which specifically addresses Improper Limitation of a Pathname to a Restricted Directory, commonly known as Path Traversal. The vulnerability exists in the server-side path resolution logic where it does not adequately validate or canonicalize file paths before executing file system operations, creating an attack surface that allows malicious path manipulation.
The operational impact of CVE-2015-8228 extends beyond simple unauthorized file access, as it provides attackers with potential access to critical system information and configuration files. An attacker who successfully exploits this vulnerability could retrieve sensitive data including router configuration files, user credentials stored in configuration databases, system logs, and potentially other system files that may contain valuable information for further attacks. This vulnerability also aligns with ATT&CK technique T1078 which covers Valid Accounts, as it allows attackers to leverage existing authenticated sessions to escalate privileges and access restricted resources. The implications are particularly severe for network infrastructure devices, as these routers often serve as gateways and may contain information about network topology, access controls, and other sensitive operational data.
Mitigation strategies for this vulnerability should focus on immediate firmware updates to the affected Huawei router models, specifically targeting software versions V200R006SPH003 or later where the vulnerability has been addressed. Organizations should also implement network segmentation and access controls to limit the potential impact of such vulnerabilities, ensuring that only authorized personnel can access the affected devices. Additionally, monitoring for unusual SFTP access patterns and implementing intrusion detection systems can help identify potential exploitation attempts. The vulnerability highlights the importance of maintaining current firmware versions and conducting regular security assessments of network infrastructure devices. Security teams should also consider implementing network access controls that limit direct SFTP access to these devices, and establish robust change management procedures to ensure timely patch deployment across all affected network equipment.