CVE-2018-15357 in ESP-200
Summary
by MITRE
An authenticated attacker with low privileges can extract password hash information for all users in Eltex ESP-200 firmware version 1.2.0.
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Analysis
by VulDB Data Team • 03/16/2020
The vulnerability identified as CVE-2018-15357 represents a critical authentication bypass and credential exposure flaw within the Eltex ESP-200 network device firmware version 1.2.0. This issue stems from inadequate access control mechanisms that fail to properly validate user privileges before exposing sensitive authentication data. The vulnerability specifically affects authenticated users who possess low privilege levels, demonstrating a fundamental flaw in the firmware's permission model where restricted access users can escalate their information gathering capabilities beyond their designated privileges.
The technical implementation of this vulnerability resides in the firmware's user authentication and session management subsystem where insufficient input validation and privilege checking allows malicious actors to exploit a weakness in the password hash extraction process. When authenticated users make specific API calls or request particular system endpoints, the firmware fails to properly verify that the requesting user has adequate permissions to access password hash information. This flaw operates under the principle of insufficient authorization checks as defined by CWE-285, where the system does not adequately verify that the user has sufficient privileges to perform the requested operation. The vulnerability manifests through the system's failure to implement proper access control lists or role-based permissions that would normally restrict access to authentication data.
The operational impact of this vulnerability extends far beyond simple information disclosure, as it provides attackers with comprehensive password hash information for all users within the system. This exposure creates an immediate risk for credential compromise and subsequent lateral movement within network environments. Attackers can leverage the extracted hash information to attempt password cracking using various techniques including rainbow table attacks, brute force methods, or credential stuffing attacks against other systems within the network perimeter. The vulnerability essentially undermines the entire authentication infrastructure of the device, as the password hashes represent the foundation upon which user access control relies. This type of vulnerability aligns with ATT&CK technique T1078 which covers valid accounts and credential access, where adversaries use legitimate credentials to gain access to systems and network resources.
Mitigation strategies for CVE-2018-15357 require immediate firmware updates from Eltex to address the underlying access control implementation flaws. Organizations should implement network segmentation to limit the exposure of affected devices and establish monitoring for unusual authentication-related activities. The vulnerability highlights the importance of proper privilege separation and access control implementation, which should follow security best practices such as the principle of least privilege and defense in depth. Additionally, system administrators should conduct comprehensive security assessments of all network devices to identify similar authorization flaws and implement multi-factor authentication mechanisms where possible to reduce the impact of credential exposure. The vulnerability demonstrates how basic access control failures can create cascading security issues that compromise entire network infrastructures and emphasizes the necessity of regular security audits and vulnerability assessments.