CVE-2017-10614 in Junos
Summary
by MITRE
A vulnerability in telnetd service on Junos OS allows a remote attacker to cause a limited memory and/or CPU consumption denial of service attack. This issue was found during internal product security testing. Affected releases are Juniper Networks Junos OS 12.1X46 prior to 12.1X46-D45; 12.3X48 prior to 12.3X48-D30; 14.1 prior to 14.1R4-S9, 14.1R8; 14.2 prior to 14.2R6; 15.1 prior to 15.1F5, 15.1R3; 15.1X49 prior to 15.1X49-D40; 15.1X53 prior to 15.1X53-D232, 15.1X53-D47.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 01/03/2023
The vulnerability identified as CVE-2017-10614 represents a denial of service weakness within the telnetd service component of Junos OS network operating systems. This security flaw specifically targets the telnet daemon implementation that provides remote terminal access services to network devices. The vulnerability manifests during normal operational conditions when legitimate remote connections are established, creating a scenario where an unauthenticated remote attacker can exploit the service to consume excessive system resources. The issue was discovered through internal security testing procedures conducted by Juniper Networks, indicating that it was identified before public disclosure, which demonstrates the vendor's proactive security assessment capabilities. The affected versions span multiple release branches including 12.1X46, 12.3X48, 14.1, 14.2, 15.1, and 15.1X49, reflecting the widespread nature of this particular implementation flaw across the Junos OS ecosystem.
The technical root cause of this vulnerability lies in improper resource management within the telnetd service handling mechanism. When remote connections are established through the telnet protocol, the service fails to properly validate or limit resource consumption patterns, leading to potential memory exhaustion or CPU overutilization conditions. This flaw operates at the application layer of the network stack and specifically affects how the telnet daemon processes incoming connection requests and maintains session states. The vulnerability does not appear to enable arbitrary code execution or privilege escalation, but rather focuses on resource exhaustion that can lead to service unavailability. The issue is classified under the Common Weakness Enumeration framework as a weakness related to resource management and improper handling of resource consumption patterns, which aligns with CWE-400 categories for unspecified resource management issues. This weakness can be categorized under the ATT&CK framework as a denial of service technique that leverages service-level vulnerabilities to disrupt normal operations.
The operational impact of this vulnerability extends beyond simple service disruption, as it can potentially compromise the availability of critical network infrastructure components. Network administrators managing devices running affected Junos OS versions face the risk of unauthorized parties causing service interruptions that could affect network management accessibility and operational continuity. The vulnerability affects devices that rely on telnet for administrative access, which, while less common in modern deployments due to security concerns, still represents a significant attack surface in legacy network environments. Organizations with multiple affected devices across their network infrastructure could experience cascading effects if the denial of service conditions propagate through interconnected systems. The resource consumption patterns associated with this vulnerability suggest that attackers could potentially maintain prolonged attack sessions, making the impact more persistent and difficult to mitigate through simple service restarts.
Mitigation strategies for CVE-2017-10614 focus on both immediate remediation and long-term architectural improvements. The primary recommendation involves upgrading affected Junos OS versions to the patched releases specified by Juniper Networks, which include versions 12.1X46-D45, 12.3X48-D30, 14.1R4-S9, 14.1R8, 14.2R6, 15.1F5, 15.1R3, 15.1X49-D40, 15.1X53-D232, and 15.1X53-D47. Network administrators should also implement network segmentation and access control measures to limit exposure of telnet services to trusted networks only. Additional defensive measures include monitoring for unusual connection patterns and implementing rate limiting mechanisms at network boundaries to detect and prevent exploitation attempts. The vulnerability highlights the importance of maintaining current security patches and demonstrates the necessity of regular security assessments for network infrastructure components. Organizations should also consider migrating away from telnet protocols entirely in favor of more secure alternatives such as ssh protocols, which provide better authentication mechanisms and are less susceptible to this type of resource exhaustion attack.