How can you secure VoIP protocols from cyberattacks?

Implement end-to-end encryption to protect the content of voice calls. Secure protocols like Secure Real-time Transport Protocol (SRTP) can be used for this purpose, Use strong encryption algorithms and key management practices to prevent eavesdropping and data tampering. Employ firewalls and intrusion detection/prevention systems (IDPS) to monitor and filter incoming and outgoing VoIP traffic. Isolate VoIP traffic on a separate VLAN to minimize the risk of unauthorized access. Implement strong authentication mechanisms, such as multi-factor authentication (MFA), for users and devices accessing the VoIP system. Ensure sufficient network bandwidth and quality of service (QoS) mechanisms to maintain a high-quality VoIP experience.

To enable and validate that you have this VoIP encryption capability, please check the firmware on your VoIP phones. The manufacturer should clearly publish what kind of encryption algorithms are supported. Next, check with corporate security policy to ensure that these algorightms are strong enough as per the policy.

You need to check also the version/revision of the mentioned encryption algorithms since not all of them are considered safe right now.

As Voice over Internet Protocol (VoIP) services grow in popularity, it's important to address the security risks involved. Cyber attackers often exploit vulnerabilities in VoIP protocols, compromising privacy and sensitive information. Understanding VoIP Protocols: VoIP protocols facilitate voice and multimedia transmission over the internet. However, these protocols can be targeted by cyber attackers due to the transmission of sensitive data. With the growing use of VoIP services, it's vital to prioritize the security of these protocols. By following recommended security practices, individuals and organizations can mitigate the risk of cyber attacks on VoIP systems, ensuring secure communication.

Depending on the type of the application and the type of encryption, also performance should be taken into account. Encryption/Decryption can affect processing time depending on the available computational resources.

Ideally, you should integrate authentication and authorization with your enterprise identity and access management (IAM) solution. That way you don't have to remember separate credentials just for VoIP services or using weak authentication methods.

Our company's PBX system was inundated with an unusually high volume of calls. I even received calls where the caller remained silent but managed to put the call into a conference mode. This allowed the caller to dial premium-rate numbers at our expense. The root cause? We were operating on an outdated version of Asterisk PBX, which had a known vulnerability. Newer versions had already addressed this issue. To resolve the problem, we promptly upgraded our Asterisk PBX software, thereby closing the security loophole.

In a previous role, we were deploying new Kamailio proxies to improve our VoIP infrastructure. Oddly, these proxies started receiving traffic even though their IPs weren't yet in the DNS. We used Prometheus to export metrics and Grafana for monitoring, with custom metrics to identify traffic sources. Surprisingly, the traffic came from various IPs but in low volumes from each. This anomaly served as an unintended honeypot, enabling us to identify and block malicious IPs. The incident highlights the vital role of monitoring in VoIP security and the effectiveness of open-source tools like Grafana and Prometheus.

Monitor for unusual or non-VoIP sessions that originates or terminates at your VoIP phones. That is a sign that the malware has compromised the VoIP phone and using it to create unauthorized sessions, such as calling the C2 (command and control) server operated by the botnet operator.

It's important to not have the VoIp server directly exposed to the external networks. Additional HW such as firewalls and IDs should be up first in the chain in order to set proper rules. A local antivirus should also be used and constantly updated.

Along with encryption, updates and other details mentioned, "Thorough assessment" of vendors including their equipment and services for security vulnerabilities would help. A trusted vendor would add to the security. This includes making sure the service provider has regular updated checks and audits including penetration testing for identifying vulnerabilities and issues in the entire infrastructure.

One way to leverage VoIP security expert is to ask him/her to perform ethical penetration test against your VoIP systems. This exercise will reveal your readiness against cyber attacks.

Monitor call detail records for unusual calls to safeguard against corporate espionage or your phone system is being leveraged to commit toll or international revenue share fraud. For espionage cases, look for patterns that call unfamiliar numbers or countries that you don't typically do business with. For early detection on toll fraud, set your monitoring system to send you an alert when it has exceeded a certain billable amount.