CVE-2018-15359 in ESP-200
Summary
by MITRE
An authenticated attacker with low privileges can use insecure sudo configuration to expand attack surface 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-2018-15359 represents a critical privilege escalation flaw within the Eltex ESP-200 firmware version 1.2.0 that stems from insecure sudo configuration practices. This issue allows an authenticated user with minimal privileges to potentially escalate their access rights and expand their attack surface within the affected system. The vulnerability exists in the firmware's implementation of privilege management controls, specifically within the sudo command configuration that governs user permissions and access controls. Attackers exploiting this weakness can leverage the improperly configured sudo rules to execute commands with elevated privileges, effectively bypassing intended security boundaries and access restrictions that should normally prevent such privilege escalation.
The technical root cause of this vulnerability lies in the improper configuration of sudo permissions within the firmware environment. When users authenticate to the system with low privilege accounts, they are still able to leverage the sudo command to execute administrative functions without proper authorization checks. This misconfiguration typically involves overly permissive sudo rules that grant unnecessary privileges to users who should not have access to certain administrative commands or system resources. The vulnerability manifests as a failure in the principle of least privilege enforcement, where the system does not properly validate or restrict user actions based on their assigned permissions. This issue directly relates to CWE-276, which addresses incorrect permissions for critical resources, and CWE-78, which covers command injection vulnerabilities that can result from improper privilege handling. The insecure sudo configuration creates an attack vector that enables privilege escalation attacks, allowing malicious users to perform actions they should not be authorized to execute.
The operational impact of CVE-2018-15359 extends beyond simple privilege escalation to encompass broader system compromise capabilities. An attacker who successfully exploits this vulnerability can gain access to sensitive system functions, configuration files, and potentially other users' data or resources within the network. The expanded attack surface means that once an attacker establishes a foothold with low privileges, they can move laterally through the system, access critical infrastructure components, and potentially disrupt service availability. This vulnerability particularly affects network infrastructure devices where security is paramount, as the ESP-200 series routers and switches may serve as critical points of entry for network-wide attacks. The implications are significant for organizations relying on these devices for network security, as the vulnerability could enable attackers to modify network configurations, intercept traffic, or establish persistent access points within the network infrastructure. The attack surface expansion can lead to complete system compromise and unauthorized access to sensitive network resources.
Mitigation strategies for CVE-2018-15359 should focus on correcting the sudo configuration to enforce proper privilege controls and implement the principle of least privilege. System administrators should review and tighten sudo rules to ensure that only authorized users can execute specific administrative commands, while removing unnecessary permissions from low privilege accounts. The firmware should be updated to a version that addresses this specific vulnerability, as Eltex has likely released patches or newer firmware versions that correct the sudo configuration issues. Network segmentation and monitoring should be implemented to detect unauthorized sudo usage patterns and potential exploitation attempts. Additionally, implementing role-based access controls and regular security audits can help identify and remediate similar privilege escalation vulnerabilities. Organizations should also consider implementing multi-factor authentication for administrative access and establishing strict logging and monitoring of sudo command usage to detect anomalous behavior. The remediation process should align with security frameworks such as NIST SP 800-53 controls for privilege management and access control, ensuring that the solution addresses both the immediate vulnerability and broader security posture improvements. Regular vulnerability assessments and penetration testing should be conducted to identify similar insecure configurations in other system components and maintain an effective defense-in-depth strategy.