Eavesdropping Attacks

The most common type of attack with clear text data is eavesdropping. In an eavesdropping attack, a person examines the contents of packets as they are transmitted between two devices. Some types of applications and protocols are susceptible to eavesdropping attacks, including Telnet, POP, HTTP, TFTP, FTP, Simple Management Network Protocol (SNMP), and others.

With all of these applications and protocols, authentication information, like usernames and passwords, is passed, in clear text, between two devices. A hacker can use this information to execute access and other types of attacks.

Note

Even though some protocols might send information in clear text, they, in many cases, have a minimal authentication method to verify an individual's identity before allowing that person access to a resource. For example, applications such as Telnet, POP, and SMTP allow for authentication, even though the authentication information is sent in clear text. Actually, these protocols initially were not designed for security, but to solve specific connectivity problems. However, things have changed since these applications were developed in the 1970s, 1980s, and early 1990s, especially with the explosion of Internet usage.

Eavesdropping Tools

Typically, a protocol analyzer is used to examine (sniff) packets. The analyzer can be a hardware-based solution or a PC with a promiscuous network interface card (NIC) and appropriate software. For this kind of attack to work, the attacker must have access to a connection between the actual source and destination devices.

There are two main categories of protocol analyzers: general and attack. A general protocol analyzer captures all packets it sees and typically is used as a diagnostic tool to troubleshoot problems. There are many freeware, software-based protocol analyzers available that perform this function.

An attack protocol analyzer, on the other hand, is an enhanced form of a general protocol analyzer. Attack protocol analyzers look at certain types of applications and protocols for authentication, financial, and security information. An attacker will use this specific information to execute other types of attacks.

Eavesdropping Solutions

Sensitive information includes credit card information, personal information, Social Security numbers, telephone numbers and addresses, usernames and passwords, and proprietary information. Because many protocols and applications are insecure when transmitting sensitive information (they send their information in clear text), protection becomes necessary. One Page

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