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Apache Security - Ivan Ristic [165]

By Root 2023 0
Black-box testing can be treated as hostile and often illegal. If you are doing a favor for a friend, get written permission from someone who has the authority to provide it.

Ask yourself these questions: Who am I pretending to be? Or, what is the starting point of my assessment? The answer depends on the nature of the system you are testing. Here are some choices:

A member of the general public

A business partner of the target organization

A customer on the same shared server where the target application resides

A malicious employee

A fellow system administrator

Different starting points require different approaches. A system administrator may have access to the most important servers, but such servers are (hopefully) out of reach of a member of the public. The best way to conduct an assessment is to start with no special privileges and examine what the system looks like from that point of view. Then continue upward, assuming other roles. While doing all this, remember you are doing a web security assessment, which is a small fraction of the subject of information security. Do not cover too much territory, or you will never finish. In your initial assessment, you should focus on the issues mostly under your responsibility.

As you perform the assessment, record everything, and create an information trail. If you know something about the infrastructure beforehand, you must prove you did not use it as part of black-box testing. You can use that knowledge later, as part of white-box testing.

Black-box testing consists of the following steps:

Information gathering (passive and active)

Web server analysis

Web application analysis

Vulnerability probing

I did not include report writing, but you will have to do that, too. To make your job easier, mark your findings this way:

Notices

Things to watch out for

Warnings

Problems that are not errors but are things that should be fixed

Errors

Problems that should be corrected as soon as possible

Severe errors

Gross oversights; problems that must be corrected immediately

Information Gathering

Information gathering is the first step of every security assessment procedure and is important when performed as part of black-box testing methodology. Working blindly, you will see information available to a potential attacker. Here we assume you are armed only with the name of a web site.

Information gathering can be broadly separated into two categories: passive and active. Passive techniques cannot be detected by the organization being investigated. They involve extracting knowledge about the organization from systems outside the organization. They may include techniques that involve communication with systems run by the organization but only if such techniques are part of their normal operation (e.g., the use of the organization's DNS servers) and cannot be detected.

Most information gathering techniques are well known, having been used as part of traditional network penetration testing for years. Passive information gathering techniques were covered in the paper written by Gunter Ollmann:

"Passive Information Gathering: The Analysis Of Leaked Network Security Information" by Gunter Ollmann (NGSS) (http://www.nextgenss.com/papers/NGSJan2004PassiveWP.pdf)

The name of the web site you have been provided will resolve to an IP address, giving you the vital information you need to start with. Depending on what you have been asked to do, you must decide whether you want to gather information about the whole of the organization. If your only target is the public web site, the IP address of the server is all you need. If the target of your research is an application used internally, you will need to expand your search to cover the organization's internal systems.

The IP address of the public web site may help discover the whole network, but only if the site is internally hosted. For smaller web sites, hosting internally is overkill, so hosting is often outsourced. Your best bet is to exchange email with someone from the organization. Their IP address,

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