CVE-2020-29666 in M3 ATM Monitoring System
Summary
by MITRE • 12/10/2020
In Lan ATMService M3 ATM Monitoring System 6.1.0, due to a directory-listing vulnerability, a remote attacker can view log files, located in /websocket/logs/, that contain a user's cookie values and the predefined developer's cookie value.
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Analysis
by VulDB Data Team • 12/15/2020
The vulnerability identified as CVE-2020-29666 affects the Lan ATMService M3 ATM Monitoring System version 6.1.0, presenting a critical directory listing flaw that exposes sensitive authentication data to remote attackers. This directory traversal vulnerability specifically targets the /websocket/logs/ directory path where the system stores log files containing session information. The flaw represents a direct violation of secure coding practices and demonstrates poor access control implementation within the application's file system handling mechanisms.
The technical nature of this vulnerability stems from the system's failure to properly restrict access to sensitive directories, allowing unauthorized remote users to enumerate and retrieve files from the websocket/logs/ path. When attackers can access these log files, they gain visibility into cookie values that represent user sessions and authentication tokens. The presence of both regular user cookies and a predefined developer cookie value within these log files creates a particularly dangerous scenario for system security. This exposure enables attackers to potentially hijack user sessions or gain elevated privileges through the developer cookie, which typically contains administrative access credentials or elevated permissions.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates opportunities for session hijacking and privilege escalation attacks. Attackers who obtain valid cookie values can impersonate legitimate users or administrators, potentially gaining access to restricted system functionalities and sensitive data. The vulnerability affects the authentication and session management components of the system, undermining fundamental security controls that protect user sessions and prevent unauthorized access. This weakness in the monitoring system's architecture creates a backdoor that could allow attackers to maintain persistent access to the ATM network infrastructure while remaining undetected.
Security mitigation strategies should focus on implementing proper access controls and restricting directory traversal capabilities within the application. The system must enforce strict file access policies that prevent unauthorized enumeration of sensitive directories, particularly those containing session data or authentication tokens. Network segmentation and firewall rules should be implemented to restrict access to the websocket/logs/ directory from external networks, while internal access controls should be strengthened to prevent unauthorized file system access. The application should also implement proper log rotation and sanitization practices to ensure that sensitive information is not stored in plaintext within log files, and that session management mechanisms properly invalidate and rotate authentication tokens. This vulnerability aligns with CWE-548, which addresses information exposure through directory listing, and represents a clear violation of the principle of least privilege and secure access control implementation. The attack vector described in this vulnerability maps to ATT&CK technique T1566, specifically focusing on credential access through unsecured network services, and highlights the critical need for proper input validation and access control mechanisms in network monitoring systems.