Qué hacer en una aplicación web para que no sea segura

El artículo Lessons in website security anti-patterns by Tesco emplea el sitio web de Tesco, como ejemplo que lo que no se debe hacer en una aplicación web. Paso a paso, muestra y explica multitud de errores de seguridad que presenta este sitio web de esta gran empresa.

Al final ofrece los siguientes consejos:

1. Password storage should always be done using a strong hashing algorithm. IT should be one designed for password storage and also use a cryptographically random salt. It also must be a slow hashing algorithm – read Our password hashing has no clothes if this is a foreign concept.
2. Password retrieval should never happen. Indeed it can’t if you’ve implemented the previous step correctly. Always implement a secure password reset process. Read Everything you ever wanted to know about building a secure password reset feature for some tips on this.
3. Never mix HTTP content into your HTTPS pages. If HTTPS is important to you – and it should be – either explicitly refer to the HTTPS protocol in your references or even easier, use protocol relative URLs. There’s plenty of info in OWASP Top 10 for .NET developers part 9: Insufficient Transport Layer Protection.
4. Always send authentication cookies over HTTPS. These are almost as valuable as the password itself; it gives anyone who holds them the rights to perform any tasks the user who originally authenticated to the system can. See the link in the previous point for more information.
5. There should never be restrictions on password entropy. Don’t exclude special characters, don’t chop the length at a short, arbitrary limit (if you have to, make it 100 chars or so) and definitely don’t implement a system which is case-insensitive. See Who’s who of bad password practices – banks, airlines and more for more common mistakes.
6. Ensure basic security configurations are correct. Tracing is off, custom errors are on, a default redirect page exists, debug mode is off, etc. This is obviously for ASP.NET, but there are parallels in other web stacks. Check your .NET apps with ASafaWeb.