Understanding symbols and injections in the web codes.

Programs need to be interpreted and executed by the dedicated modules. They have definite sequences of instructions indicating to the interpreter how to perform the requested tasks. However, the codes and the platforms are made with breaches that allow malicious actions to be performed. The most famous are the injections of specific symbols in order to corrupt the instructions sequence and break the program in a way to make it open to bad practices. Besides, injections interest perhaps all programming languages, yet some are more sensitive. The following text will discuss the injections and their impacts, as well as the most critical languages versus these malicious codes.

The reserved symbols and their importance in web development:

The web development languages used by a freelance web designer Singapore share with the system programming languages a list of special characters or symbols that have particular roles. In fact, these symbols need to be used properly and in their appropriate locations in order to obtain the best functioning of the code lines.

The list contains, and is not limited, the following symbols: &, !, %,@, ;, \, < >, , /, $,

In the web development, the misuse of these symbols can result in dangerous behavior of the web page. Indeed, the browser will be forced to display the code lines that are written before the occurrence of the symbol.   

Defining the injections:

The term injection or code injection is the insertion of some lines of code in the running program in order to compromise the proper functioning. The injection can, indeed, disturb the whole process and result in data revealing, database access, sensitive data theft, and can also create dangerous breaches in the security system.

In sum, there are four types of injection attacks:

  • SQL injections:  the attack is about altering the SQL queries in order to access the database content.
  • Script injections: the attack is about adding a script that will hide in the web page. It will be activated the next time the page is loaded.
  • Shell injections: the attack uses the ability to execute the command line. This attack is known to be popular in Linux shell.
  • Dynamic evaluation: this attack exploits the eval() function call in order to have control over an application.

These examples resume the most popular attack types. Some other new attacks are developed daily, especially with the technological development and the high number of platform vulnerabilities.

The popular use of symbols to perform code injections:

The common forms of attacks use the special characters &, |, and ;. The two first act by including a Boolean behavior to the code line; the desired command would be executed regarding a particular condition (true or false).

The semi-column is used to break the code and reveal the hidden parameters.

The anti-slash is known to announce a set of attributes to the current line, as it is associated with editable outputs (print, echo, write).

The dollar ‘$’ symbol can announce the beginning of the command line (Perl) and can specify the variable (PHP).


The use of symbols to perform injection attacks is associated with the platform bugs and vulnerabilities. The technological development has definitely brought new features but also has brought new issues. Luckily, developers are still fighting against theft in order to prevent hacks, and provide fixes as well.