All posts by alex

Thoughts on the CREST CRT

Continuing my thoughts on exams series (see CISSP & CPSA) here are some notes on the CREST CRT. These are notes to help you prep, they are not the answers – CREST have a robust NDA and I have no intention of breaking it!

Pre-Reqs

You will need to have sat and passed the CPSA MCQ at a Pearson Vue test centre first. You book this direct with Pearson Vue  using a credit card.

Once that’s done, book the CRT direct with CREST by filling out the form at https://www.crest-approved.org/wp-content/uploads/UK-Exam-Booking-Form.pdf and emailing it to them. Nominate a month you want to do the exam and CREST will come back to you with some dates and morning/afternoon session availability.

You’ll need to travel to Slough – the test centre is 5 minutes’ walk from the station. Although there are several car parks, I really struggled to find spaces so the train might be your best bet, especially if you have a long drive.

CREST were really helpful and friendly during the booking process so don’t be shy about dropping them a line if you have any questions.

Your laptop

You’ll need to take in your own laptop but remember that CREST will want to wipe the hard drive on it afterwards. They didn’t seem too concerned about the swish M2 SSD I had in mine, but if your drive is non-standard, drop them a line. Either clone your existing drive or build fresh onto a new disk as they’ll be hanging onto the one in the machine for a few days and you’ll be without a working machine otherwise.

Kali should get you through the majority of the test, but you’ll need a vulnerability scanner too so license up a copy of Nessus or OpenVAS. Similarly a web proxy tool like Burp will be helpful for the webby bits. If you’re sitting this exam then these will all be tools you use daily anyway. Maybe.

Make sure you’re comfortable with configuring networking on your laptop and any VMs you have. I’d recommend bridging, not NATing, if you have VMs though. You can take in a subnet crib sheet to help, or install ipcalc. As the candidate notes point out, there are 10 marks up for grabs just for getting connected.

Read through the syllabus and write down the relevant tools and switches you’ll need for each section – some of them don’t come as standard on Kali and you’ll need to install.

General strategy

Time will run away from you, even if it doesn’t usually in these kinds of tests. Be organised! It’s an open book exam so take in tool notes and crib sheets, you do not want to be scrabbling around trying to figure out the syntax for things. I found https://highon.coffee/blog/penetration-testing-tools-cheat-sheet/ to be really helpful, so save a copy of that offline somewhere.

The test network is not internet-connected, although there is a machine in the corner of the room that you can use to Google, but frankly, if you’ve gone there then move on as it’s just a time suck.

Read through the question paper first. It’s a series of MCQs, but some questions are weighted more than others, so plan your time so that you don’t miss out on some of these more valuable ones. It’s not negatively-marked, so if you get to the last 5 minutes then just guess, don’t leave answers blank.

None of this is anything the invigilators won’t tell you at the start!

Good luck!

BLE Security

It has been an interesting week.

I’ve been working at PTP for a few months now, and one of my first pieces of research has been on IoT, er, “intimate wearables”. Well, you can read it, including the snappy vulnerability name we came up with (all the best do): https://www.pentestpartners.com/security-blog/screwdriving-locating-and-exploiting-smart-adult-toys/

After that it’s been picked up by a fair few outlets, including:

There was also a lively twitter discussion from my friend Ben Goldacre which ended up involving an MP:

Which resulted in this article in The Guardian: https://www.theguardian.com/commentisfree/2017/oct/06/drive-by-sex-toy-hacking-wake-up-call-britain-internet-security-vibrators

Which I think neatly brings us back round to why I/we did the research in the first place. Yes, the headline is catchy, but it’s to highlight that although BLE has “short” range (anything up to several hundred meters which may not be what you’d think as short) it often has shockingly implemented security that can have real world physical damage.

Many commenters pointed out that unsolicited activation of, er, the “intimate wearables” might be a feature and not a bug. I’d agree, if you knew that’s what you were getting into – consent is sexy!

We’re doing some more work on the range soon, as well as some additional vulnerability disclosures on these products – watch out for those.

Update: do you use the Lovense “Body Chat” app to, er, chat? Your messages and other info are probably not as secure as you think they are.

Update 2: I did an interview with Claire Lampen for Gizmodo, exploring the legal aspects of this too: https://gizmodo.com/if-your-vibrator-is-hacked-is-it-a-sex-crime-1820007951

Thoughts on the CREST CPSA

I’ve just sat my CPSA in preparation for $newjob.

The CPSA is part of a UK government qualifications track administered by CREST for accrediting ethical security testers and their companies. You can find a fairly barebones syllabus online along with some suggested reading material.

The CPSA changed radically a couple of years back, in that it used to be open book and packaged with a practical component, the CRT. It’s now closed book, separate from the CRT (and indeed, a prerequisite for sitting the CRT) and administered in Pearson test centres in MCQ format. The only other discussion of the CPSA I’ve found is from before this change.

The exam content is under NDA and of course, the question bank will give different content to each candidate, so this discussion isn’t going to give much away. However, although I’ve worked in security for the last five years (and IT in general for twenty) I went into the exam feeling the least confident I’ve ever felt. I’d read the syllabus and most of the reading list and still really had no idea about the content or question style.

So, here’s my advice:

  • Read the syllabus thoroughly. Note that some points aren’t examinable in the CPSA but are for the CRT and vice versa.
  • If you’re actively working in pen testing and have a background in general IT, or better still, have a CISSP or GSEC then you’ll be good with just a bit of general reading up.
  • Read the question and answers thoroughly, obviously!

Good luck!

Data mangling the Piccadilly Line

TfL have been nice enough to release a data set showing how busy trains are – the train loading.

They use a 6 point scale to measure the busy-ness:

Scale Definition Actual measure on train
1 Very quiet zero to all seats taken
2 Quiet 0 to 2 customer per m2
3 Fairly busy 2 to 3 customers per m2
4 Busy 3 to 4 customers per m2
5 Very busy 4 to 5 customers per m2
6 Exceptionally busy > 5 customers per m2

As I live in West London and work in Central London I’m interested in morning eastbound and evening westbound travel.

So, bad luck if you want to get on a train at South Ealing towards Acton Town between 0800 & 0830:

In the evening it’s very busy from central London westwards between 1745 & 1830, although once you get to Gloucester Road you stand more of a chance of getting on:

The numbers seem to suggest that the loading to Rayner’s Lane is the same as Heathrow destined trains; in my experience this isn’t borne out. The data gives a hint towards this in that Acton > Northfields trains are busier for the same time window, but I wonder whether the lower frequency of Uxbridge trains skews this a bit.

Hopefully this gives you an idea of your chances of getting on a train in the morning – I’d love to see this baked into Citymapper.

 

 

💩

I’ve encountered a couple of bugs with internet-connected devices recently so I thought I’d document them in case some other poor soul had the same troubles.

Yes, I’m kinda aware I’ve brought a lot of this on myself but it does somewhat show that these things aren’t ready for primetime just yet. I’ve done the “sensible” thing and segregated IoT devices onto their own separate, firewalled VLAN although most vendors aren’t necessarily expecting this arrangement. Many devices do NAT hole punching which seems to work ok, except when there’s UDP traffic or IPv6 thrown into the mix. Explicit port forwarding seems to be on the (thankful) wane.

Nest Protect

I had a really strange experience when my Nest smoke alarms suddenly stopped checking in. They couldn’t jump on the network and even a reset failed with the cryptic error code P007(3.9). Their technical support has actually been surprisingly good but they couldn’t figure it out.

I eventually deduced that Nests will only try the first DNS server handed out to them over DHCP. If that one is broken (but a second/third/fourth is still up so name resolution is working for everyone else!) then they fail with this generic error.

Fix: make sure your primary DNS is working; Nest need to fix the bug in their firmware so they’ll failover gracefully (which you’d assume they’d do for a safety device).

Update 05/03/17: the bug doesn’t seem to have been accepted by Nest still so I guess this isn’t going to get fixed. If a single point of failure in networking for a device that’s supposed to tell you your house is on fire worries you, I guess don’t buy one?

Netatmo Welcome

I had a camera working for ages until one day it suddenly stopped and just showed “disconnected”. A reset similarly failed to get it back online and the setup process choked with generic errors about checking the internet connection etc.

Some hints from a forum led me to find that the camera runs an IPSEC tunnel back to Netatmo over UDP. This tunnel is initiated from Netatmo themselves and my stateful firewall didn’t appreciate unsolicited inbound UDP.

Fix: Permit UDP source ports 500 & 4500 from any public IP to the IP of your camera. Note that this is not port forwarding, just a firewall rule.

(I haven’t been able to pin down exact IP ranges this will come from as Netatmo use a variety of servers and they weren’t forthcoming with help.)

Philips Hue

Again, all was working super until one day geofencing and alarms broke. Trying to connect the bridge to the online account (My Hue) would literally cause the bridge to crash – it would remain on the network but be unresponsive over its mini web browser or even zigbee light switch presses.

Philips technical support haven’t been great and blame it all on home networking despite being given packet captures.

Fix: None so far

Workaround: Connect your Hue bridge into Homekit and use the automation features of Apple TV instead.

Update 05/03/17: this randomly started working again recently. Still no word from Hue support though.

Thoughts on the CISSP

Disclaimer: I’m a member of the SANS Advisory Board. SANS is a competitor certification awarding body to ISC2. None of the examples below are real questions from either exam and shouldn’t be used as revision!

isc2_cissp2I recently clicked over enough time elapsed (after deductions for my GSEC) to be eligible for the CISSP, took the exam, passed and after a wait, awarded it.

There are a reasonable number of comparisons out there between the GSEC & CISSP but none that I found that look at it after CISSP updated the common body of knowledge in 2015.

Broadly the style of the exams is similar in that they’re both computer-based proctored affairs at Pearson testing centres (CISSP used to be pen & paper!). The GSEC is shorter (180 questions against 250, 5 hours not 6) and also has the benefit of allowing one 15 minute stopped clock break at any point. The biggest difference though is that GSEC is open book, CISSP all has to be memorised: this allows the GSEC to test certain things akin to the real world like “which of these nmap switches would you use for x” (ie something you’d either google or use the help pages for). Both exams have scenario type questions: “you’re the security officer for widgets INC, which is the best firewall for a DMZ if you’re worried about DDoSs” and hotspot / drag & drop multiple correct answer types. Both allow questions to be flagged and revisited.

I found the revision for the GSEC adequately prepared me for the content and style of question I faced in the real exam. Mock tests are available, which again were fairly close to the real thing. The CISSP was not so – I read a variety of books (Eric Conrad’s), the SANS bootcamp course and the official ISC2 flashcards app but once in the exam the questions felt wildly different to anything I’d revised for. This isn’t helped by the 25 ‘wildcard’ questions thrown in that don’t count!

I’ve never failed an exam in my life but I honestly found myself at the halfway point thinking I’d failed it. Genuinely that bad. Where I could answer things quickly and confidently I did so; anything I was 90% on I answered but flagged; anything I had no clue on I left blank and flagged. The first pass left me with maybe 50 questions I had to go back and review, although I probably only changed a couple of answers on the second look. An actual advantage was gleaning information from later questions to use in earlier ones.

It’s certainly been said that to pass the CISSP you have to ‘think like a manager’ which I always felt was a bit derogatory but I think it really means to think at a high level, never be afraid to give an answer that refers to outside experts and always prioritise human safety.

The CISSP, like the GSEC, is certainly a mile wide and an inch deep – although I think the GSEC is maybe more like an inch and a half! For both, having experience in the field is certainly a blessing and a curse: you need some outside knowledge but you’re often tempted to add extra information into the questions – “I do change management differently to that at work”.

So which is the better exam? From an experience perspective I’d say the GSEC was the more ‘enjoyable’ and perhaps relevant to the day job. It certainly taught me some new things to take back to the day job too. But the GSEC is not so widely recognised so if you want to pass that automated screening bot on your next job search then maybe the CISSP is the one to go for.