domain user as app pool identity - a security hole?

We are developing 开发者_运维知识库a couple of web applications and web services for our intranet. To access resources like databases or other data sources we use technical domain users and store their credentials in the config file of the web apps. Passwords must be encrypted before written to the file. (The application then have to decrypts it to access the resources.)

We do this for quite a while but now a discussion came up. Our server operations team suddenly considers it unsecure to store the passwords in config files because an attacker might successfully decrypt it, maybe by analyzing the little tool used for encryption. (It's written in .Net so indeed it's not really hard to analyse the used algorithm by using Reflector & Co.) As an alternative they proposed to use the technical user account as app pool security context. But I'm not sure if this doesn't mean to replace one possible security hole by an actual one: If the app pool runs under the context of the domain user, the attacker dont't have to know the password anymore. He simply can use security holes in the application or try to run his own code under this app pool somehow.

What do you mean? Is there a best practice to deal with passwords in web applications?

Thanks, Rocko

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Its a very common practice for a domain user to run the app. Just ensure that account has a really small footprint - only what is needed.