Penetration Testing and Vulnerability Scans

In our compliance services, oftentimes, we are tasked to assist our clients in security testing – either conducting those ourselves, or to verify previously conducted tests for compliance purposes. There are many occasions where clients decide to perform the scanning on their own, aside from the obvious option of engaging another party to do this. When we receive the test reports from our client to verify, that’s when the excitement begins.

The fundamental question we often face is, what should a penetration testing report look like? What does a vulnerability scan looks like? This age old question has been haunting PCI-DSS for years, so much so that the council decided to publish a guidance on this, found: https://www.pcisecuritystandards.org/documents/Penetration_Testing_Guidance_March_2015.pdf

It’s a good read, if not fairly simplified, but it seeks valiantly to answer the question of what is a penetration testing vs vulnerability scans. This is important, because in PCI-DSS, the latter needs to be done quarterly, while the former needs to be done annually. When you multiply that by the costs and number of assets in scope, we could be looking at a decision involving tens of thousands of dollars.

In the document, section 2.1 dives into this and attempts to seek a differentiation between these two. In the basic concept of penetration testing methodology, these two activities serve specific purposes, for instance in the activities of Discovery, Enumeration, Footprinting, Exploitation, Cleanup etc, depending on which approach you take. And while there are many ways to explain the differences, to summarise:

A penetration test can be a vulnerability assessment (or scan, we will use interchangeably for the sake of this article) and beyond, while a vulnerability scan is not a penetration test.

A Penetration test can be initiated with a vulnerability assessment. The result from the vulnerability assessment will be used by the tester to penetrate or perform a more detailed assessment to circumvent controls or exploit the discovered vulnerabilities. In the process, the tester will also use manual methods to “test” the vulnerable system and likely during this process of poking around, discover more vulnerabilities or loopholes in the system that may not be detected during the initial scan. In the presentation of the findings of a penetration testing report, typically the ‘Proof of Concept’ (POC) detailing how the vulnerability was exploited will be documented.

Vulnerability assessment is the process to find out known vulnerabilities by using an (oftentimes) automated method (such as scanning software or scripts) against the targeted system. The result of the scanning will detail down the vulnerabilities, the risk exposures and action that can be taken to remediate these vulnerabilities. There is typically no manual proof of concepts that is done in the penetration test. The objective of a vulnerability assessment is to discover and report known vulnerabilities, not to exploit them.

A penetration test will normally take longer time to complete, i.e. few days, considering the manual verification or activities that need to be carried out to ‘penetrate’ the vulnerabilities. A vulnerability assessment can be completed in a shorter time frame, depending on the size of scope and software installed on the target system and it can be run on automated or scheduled basis. In our vulnerability scans, we also refine the results further by eliminating false positives, such as a patch that might not have been applied, but other secondary controls like virtual patching are in place to mitigate the risks. In either case, these are different activities, and in PCI, we need to understand what is NOT Penetration Testing.

We once received a 250 page report from our client who proudly said this was a professional work done by an outsourced security testing company offshore. Surprised as such a tome, which we assumed must have excerpts of Tolkien’s Lord of The Rings in there for good measure – we went through it. We found that it was nothing more than a raw report of the entire software inventory of the entire scope of around 50 plus assets. Meaning it listed down in excruciating detail what are the software installed in each of these systems, the licenses the OS versions etc. It was nothing more than a dump of the system’s software and nothing more. Not even the courtesy vulnerability scan. We told our bright eyed customer that we cannot accept this, and while this is a good book to have in terms of detailing the software they have, it has nothing to do with penetration testing, or vulnerability assessment. From singing praises of the offshore company, he ended up throwing them invectives that would make a pirate cringe.

We do need to be careful. We are not saying that the entire industry is filled with such charlatans peddling so called pentest services for a song and giving you a report that only provides you with the figurative emperor’s clothing for your security needs…but we must be able to differentiate what is, and what is not, security testing.

If you have further questions on security testing, drop us a note at avantedge@pkfmalaysia.com and we can quickly assess your needs and advice you on your next options to take.

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