Analysis: The critical weakness of VoIP in the cradle of Security Crisis

So far, we have not seen large-scale attack events in the already used VoIP system, but this does not prove that VoIP itself is very safe, the reason is that the current scale of the VoIP system is not large enough and has not attracted the widespread attention of hackers. we can imagine that once the explosive growth of VoIP, hackers will pay more attention to it, at that time, various security problems will be exposed one by one. Therefore, for enterprises that have deployed or are planning to deploy VoIP systems, from now on, we must truly understand the possible security risks faced by the VoIP system, and adopt appropriate measures to provide greater protection.

As one of the next-generation communication technologies, VoIP is widely used because of its low price advantages and the ability to easily expand multiple applications. However, the features of its transmission over an IP network also keep people worried about its security. This article will share with you the security risks faced by VoIP.

VoIP can be said to be an application of the Internet. It is an application of the network, just like email, instant message, and Web page searching. It can be transmitted between devices connected to the Internet, such as computers, handheld devices, handheld devices, and wireless devices.

Technically speaking, VoIP transmits voice over the Internet through data packets. Therefore, the attack methods we are familiar with on the internet can generally be used to threaten the security of VoIP.

Basic Network risks caused by VoIP Devices

Like other network devices or servers, the security of VoIP devices is the first challenge. Currently, most VoIP devices are based on standard operating systems, and some use Windows NT operating systems, some Linux-based operating systems are highly vulnerable to attacks.

According to my understanding, many well-known VoIP manufacturers in China use Linux operating systems. Although the security is relatively high, some security threats cannot be avoided. In principle, vulnerabilities can be exploited to initiate various types of attacks.

To the extent of security threats, once the core VoIP system is attacked by hackers, the damage will undoubtedly be incalculable. On the one hand, IP phones can be called without authentication, unprotected voice calls may be intercepted and eavesdropped, and can be intercepted at any time. On the other hand, the account information of existing users is undoubtedly not guaranteed.

In addition, in most cases, VoIP facilities need to provide remote management capabilities, and the services and software they depend on may also have security vulnerabilities. If improperly configured, hackers can also use these vulnerabilities to access the system as administrators. Once they enter the system, the company's internal network is completely transparent to hackers, it can not only launch attacks on the VoIP device itself, but also launch attacks on the company's basic network, resulting in the company's network paralysis and data loss, so the consequences are quite serious.

As far as I know, a small VoIP operator in China uses the Red Hat 7.3 network Guard System and MySQL database. For the convenience of remote management, we opened the Webmin service. One day, we suddenly found data loss in the database. After technical analysis, we found someone intruded into the network guard using Webmin and deleted user data, fortunately, the operator backs up databases every day without causing too much economic losses. If there is no backup, the attack on the operator can be said to be fatal.

In addition, VoIP devices are bound to face the threat of denial-of-service attacks. Once a large number of packets are used to initiate attacks on VoIP devices, requests from normal users will be ignored, thus, the user's normal use cannot be guaranteed.

If the VoIP infrastructure cannot be effectively protected, it can be easily attacked. Compared with traditional telephone devices, the network used to transmit VoIP protocol routers, servers, and even switches are more vulnerable to attacks. The traditional PBX is stable and secure. The transmission carrier of VoIP is an IP network. As an open network, its inherent data network security vulnerability may cause the following security risks during the transmission of VoIP signals.

1. voice packet sniffing and listening

Currently, when deploying and testing a VoIP network, many VoIP service providers usually use a method to test the quality of voice calls by capturing packets, then it is restored to a digital voice signal and played on the computer. As we can imagine, once our voice data packets are intercepted by hackers, there should be a way to convert them into digital voice signals, therefore, during the call, personal information such as privacy and bank card information will be exposed to hackers.

2. Web identity spoofing and free use of services

Client Authentication for many VoIP services is based on the user name and password. Therefore, once hackers obtain user information through various means, they can call the user's account and password at will, fees are calculated by users.

3. Spam information harasses VoIP users

In the future, the spread of spam may also occur on the VoIP system. Hackers use directories that are the same as those for email addresses to obtain attacks, find a large number of legitimate IP Phone addresses, and then place a wav file on a computer, A large number of spam voice mails can be sent, and fake IP Phone addresses can be used to prevent tracing.

4. network line quality is directly related to VoIP Quality

Nowadays, many VoIP manufacturers are faced with a dilemma. First, they use dedicated lines to build a network dedicated to VoIP. Although this option can ensure the stability and high quality of VoIP transmission signals, however, it is clear that the cost is too high. However, to allow VoIP signals to run on the public network, this method is highly cost-effective and feasible. In fact, most VoIP manufacturers also adopt this method. However, there are obviously too many uncertainties in this approach.

A large telecom operator in China has always had a VoIP service. In order to combat competitors and develop their own services, the operator has adopted the practice of blocking servers or VoIP addresses of other VoIP vendors without interrupting the network. This gives users the feeling that the VoIP service is unstable and sometimes can be used up, sometimes, you may choose to give up the service or choose services from other manufacturers.

1. Research on VoIP Security Technology
2. Integrated solutions to solve VoIP Security Problems