Testing: Information Gathering
A security testing needs a first phase focused on collect all the information about the application. Information Gathering is a necessary step before the real activity of penetration test.
This task can be carried out searching on different sources and with many methods using public tools as search engine, using fictitious requests purposely forged to receive error messages that give back the versions and technologies used for the application or analyzing and discovering the front-end/back-end infrastructure and applications with the purpose to collect many other useful information.
Often it’s possible to gather this information by receiving a response from the application targets because there're old and backup files or default bad configurations not changed from administrators on web server.
The application discovery testing is an activity oriented to the identification of the web applications hosted on a web server.
This analysis is important because many times there isn't a direct link with the main application and for this reason a discovery analysis is useful to notice every web-app used for administration, old versions or others never deleted and created for a test development phase.
This phase of the Information Gathering process consists in a browsing and capturing of the resources find on the web but the operations that are possibile to perform in this analysis consist also in the collection of the information available on the search engines and extractable using the their particular functionalities.
The web applications provide during a penetration test many information (as error codes) about technologies and products using particular requests forged expressly for this scope.
Often to find these information it isn't need to have particular skills because the web applications with errors on the source code or with infrastructural problems provide these data themselves.
Often an analysis on the infrastructure and topology architecture can reveal a lot of information about a web application as source code, HTTP methods allowed, administration functionalities, authentication methods and infrastructural configurations. For this reason a verify only on the web applications can't be an exhaustive test considering the very large number of information that it's possible to obtain during a security assessment analyzing all the components present in a network.
During the configuration of a database server many DB administrators don't consider the importance of the security about DB Listener component which reveals sensible data as some kinds of configurations and database istances running.
The collection of these information can provide the needful elements to compromise the reservedness, integrity and availability of the data stored.
An accurate security analysis over DB listener configuration problematics permits to acquire these information.
The web applications hide some information which usally not cosidered during the development or the configuration.
These data can be discovered in the source code, in the log files or in default error codes of the web servers so a correct approach on this problematic is fundamental during a security assessment.
Observing the file extension present in a web server and so used for a web-app it's possible to comprehend the technologies which compose the applications (for example jsp and asp extensions in a server-side architecture) and the others systems linked to it.
The files contained in a web server (as old, backup and renamed files), freely readble and downloadble are a big source of information so it's necessary to verify the presence of these data because many times contain parts of source code, installation paths and sometimes also passwords for applications and/or databases.
OWASP Testing Guide v2
Here is the OWASP Testing Guide v2 Table of Contents