Disadvantages

Since JavaScript is basically a client-side scripting language, it can potentially introduce security issues by means of malicious implementations of the language. These issues can easily arise if the user is not careful enough and unknowingly causes the execution of malicious code. Some of these are mentioned.

These security issues are in no way a disadvantage of the language itself.

• Cross-site scripting (XSS)

• Cross-site request forgery

• JavaScript hijacking

• Browser and plugin coding errors

• Sandbox implementation errors

• Malicious/Vulnerable libraries and frameworks

Some other disadvantages of JavaScript which are not security issues but can be generated by the user.

Again these are in no way a disadvantage of the language itself.

• Potential loss of web page functionality due to user disabling JS script execution. This cannot be validated by the server because JS is client-side only.