CVE-2018-4059 in coTURN
Summary
by MITRE
An exploitable unsafe default configuration vulnerability exists in the TURN server function of coTURN prior to version 4.5.0.9. By default, the TURN server runs an unauthenticated telnet admin portal on the loopback interface. This can provide administrator access to the TURN server configuration, which can lead to additional attacks. An attacker who can get access to the telnet port can gain administrator access to the TURN server.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/03/2023
The vulnerability described in CVE-2018-4059 represents a critical security flaw in the coTURN implementation that exposes an unauthenticated administrative interface through an unsafe default configuration. This issue affects versions prior to 4.5.0.9 and specifically targets the TURN server functionality that is commonly used in WebRTC applications for NAT traversal and media relay services. The vulnerability stems from the software's default deployment configuration where the telnet admin portal operates on the loopback interface without any authentication mechanisms, creating an inherent security risk that can be exploited by unauthorized parties.
The technical flaw manifests as an insecure default configuration where the TURN server's administrative interface remains accessible without proper authentication controls. This unauthenticated telnet portal operates on the loopback interface, meaning it is bound to the localhost network interface and should theoretically only be accessible from within the same machine. However, due to the lack of authentication requirements, any attacker who can reach this port can gain full administrative access to the TURN server configuration. The vulnerability is particularly dangerous because it allows attackers to modify server settings, potentially leading to service disruption, data exfiltration, or further compromise of the network infrastructure.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it provides attackers with complete administrative control over the TURN server. This level of access can enable attackers to modify TURN server configurations, add or remove users, change authentication parameters, and potentially redirect traffic through compromised relay services. The implications are significant for organizations using coTURN in production environments, as the vulnerability could be exploited to create persistent backdoors, establish unauthorized relay channels, or disrupt legitimate communication services. The attack surface is further expanded when considering that TURN servers are often deployed in network environments where the loopback interface might be exposed or where attackers can gain local access to the system.
Security practitioners should implement multiple layers of mitigation to address this vulnerability. The primary recommendation is to upgrade to coTURN version 4.5.0.9 or later, which includes proper authentication mechanisms for the administrative interface. Organizations should also consider implementing network segmentation to restrict access to the telnet admin port, disable the admin portal entirely if not required, and configure proper firewall rules to prevent unauthorized access. Additionally, monitoring for unusual administrative access patterns and implementing intrusion detection systems can help identify potential exploitation attempts. This vulnerability aligns with CWE-284, which addresses improper access control, and maps to ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting, highlighting the need for comprehensive security measures beyond simple patching.