SecurityGen study highlights hidden threat to 5G mobile networks from GTP-based attacks

Mobile operators need to reassess security vulnerabilities in the key GTP (GPRS Tunnelling Protocol) protocol and bolster GTP security within their networks as they continue to invest in and roll out 5G, according to a new study by SecurityGen, the global provider of security solutions and services for the telecom industry. 

SecurityGen’s latest report, GTP vulnerabilities: A cause for concern in 5G and LTE networks, is based on 150 telecom security assessments of 39 live mobile networks during 2022 and 2023. It found that nearly 77% of networks had no cybersecurity measures in place against GTP-based attacks. Only 23% had a high level of cybersecurity measures to keep successful GTP-based test attacks to a minimum. 

“Despite its widespread use, the GTP mobile network protocol is not entirely secure and opens up opportunities for attackers to intercept sensitive user data, engage in fraudulent activities, or disrupt network services,” said Dmitry Kurbatov, Co-founder and CTO of SecurityGen. “As we explored and examined GTP’s security vulnerabilities, it became apparent that the protocol requires in-depth consideration and robust mitigation strategies to block the potential threats more so in the 5G set-up.”

The study is based on the results of over 150 telecom security assessments by SecurityGen during the last 12 months involving 39 mobile operators in 24 countries across the SEA, LATAM and MEA regions. It highlights the most critical GTP-related threats to raise awareness among mobile operators and stakeholders of the hidden vulnerabilities within the protocol.

The SecurityGen assessments found that all the tested networks exhibited some vulnerabilities in their management of the GTP protocol:

• In 71% of networks assessed, GTP-based test attacks on subscriber information disclosure were successful. Which can be used to impact subscribers, perform other attacks, target other interfaces, radio interfaces and OS and network vulnerabilities.

• 62% of networks assessed were vulnerable to fraudulent activity involving the GTP protocol. 

• 85% of networks were susceptible to targeted attacks on subscribers aimed at impeding or completely interrupting the functionality of data transmission services.

• 46% were vulnerable to network equipment denial-of-service attacks. Using this vulnerability, an attacker can simultaneously hinder network (Internet) connection for individual subscribers and many users via network equipment denial.

• User traffic interception was successful in 69% of the networks tested. By exploiting this vulnerability, an attacker can direct all incoming traffic to their equipment by altering the nodes that process the user traffic.

“Throughout our assessments, we were surprised that not a single network was protected with a GTP firewall. Even when mobile operators claimed to have a GTP firewall deployed, we could carry test attacks successfully, as there was no functional GTP firewall in place,” said Kurbatov. “This suggests that either the GTP firewall was not actively operational, or its filtering rules were not correctly configured or enabled.”

“The findings of this study should serve as a wakeup call that spurs operators and the wider telecoms industry to take action necessary to secure our interconnected digital future.”