CVE-2018-19878 in RTU950
Summary
by MITRE
An issue was discovered on Teltonika RTU950 R_31.04.89 devices. The application allows a user to login without limitation. For every successful login request, the application saves a session. A user can re-login without logging out, causing the application to store the session in memory. Exploitation of this vulnerability will increase memory use and consume free space.
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Analysis
by VulDB Data Team • 10/06/2023
This vulnerability exists in Teltonika RTU950 R_31.04.89 devices where the authentication system lacks proper session management controls. The flaw stems from the application's inability to enforce session limits or track active user sessions effectively. When users successfully authenticate, the system creates session entries that persist in memory without proper cleanup mechanisms. This design oversight allows unlimited concurrent sessions to accumulate within the device's memory resources, creating a memory exhaustion scenario that can severely impact system performance and stability.
The technical implementation of this vulnerability demonstrates a classic case of insufficient session management as classified under CWE-613. The application fails to implement proper session lifecycle controls, specifically the lack of session expiration mechanisms and resource cleanup procedures. This weakness creates a resource consumption attack vector where an attacker can continuously establish new sessions without terminating previous ones, leading to progressive memory accumulation. The vulnerability operates at the application layer and represents a denial of service condition that can be exploited through simple repeated authentication attempts.
From an operational impact perspective, this vulnerability presents a significant risk to industrial control systems and remote terminal units that rely on Teltonika RTU950 devices for critical infrastructure management. The continuous memory consumption can lead to system instability, application crashes, and ultimately complete device unavailability. Network administrators and security teams face the challenge of monitoring and managing session accumulation without proper built-in controls. This vulnerability can be particularly dangerous in environments where continuous system availability is critical for operational continuity, as it can be exploited to create service disruptions without requiring advanced technical skills or specialized tools.
The exploitation of this vulnerability aligns with ATT&CK technique T1499.004 which focuses on network denial of service attacks through resource exhaustion. Security professionals should implement monitoring solutions to detect unusual session accumulation patterns and establish automated session cleanup procedures. The recommended mitigations include implementing session limits, configuring automatic session cleanup mechanisms, and establishing network monitoring protocols to detect abnormal session growth. Device administrators should also consider implementing access controls that limit the number of concurrent sessions per user account and regularly review session logs to identify potential abuse patterns. Additionally, firmware updates should be applied promptly to address the underlying session management implementation flaws that enable this vulnerability to persist.