**4.1 UDP**

*Computer and Network Security*

assemble the original packet

that the Urgent Pointer is not used correctly.

It is possible to fill the field of any padding.

the receiving party cannot properly collect packets.

8. "Pointer Urgent" field

options are present.

9. "Options" field

information.

10."Padding" field

that the data is being injected.

**4. Result of injection**

You can modify the value of the "Window" field. Handling is only possible when the packet was built at a hidden data source. Due to the manipulations that occur on the source host, the receiving party will not be able to properly

You can modify the value of this field. This injection is only possible if all URG

So, if the Urgent Pointer is filled in and the flag of URG is not setting, it means

We could modify the data of this field. In the options, you can realize the data

TCP header option values are limited, and network analysis results in attempt-

It should be noted that manipulation is only possible if the package is made up of hidden source data. Because of the manipulation that occurs at the source,

Handling "Padding" is one of the most interesting. The "Padding" field starts after the 0x00 in the "Options" field; the value is the EOL option and takes up to 32-bit header boundaries. Interest in this manipulation is contained in the following text after the EOL does not produce a 32-bit header, which means that these bytes are invisible to network devices and sniffer. Although the analysis of this field is simple enough, the EOL up to 32-bit header boundaries must be set to "0" at the standard behind the "Options" field, causing any other value of this field to indicate

The standard TCP header field with options and fall is 192 bits. As a result of the above actions, you can use up to 150 bits, which is 78.13% of the total number of bits in the original, unmodified header. This amount of data allows the use of 18 characters in an 8-bit header in the standard ASCII character set. Therefore, after all the calculations, we get the maximum possible amount equal to 6 bits. The processed piece of information was included in the next 8 bits of the transmitted

after value 0x00, but it is not considered after this byte header data.

ing to identify a possible option that attempts to identify incorrectly filled options or unknown options whose appearance indicates a possible injection of

7. "Window" field

**82**

symbol.

User Datagram Protocol is a connectionless transport layer protocol. No connection setup is created before transferring between hosts. This protocol is less reliable than TCP, but gives a higher transfer rate with less overhead. This protocol is standardized by RFC 768.
