How to protect yourself against the Shellshock BASH vulnerability

Like many people I was quite shocked to learn about the recent vulnerability in BASH that can leave servers wide open to attack. My SugarCRM system has been running on Ubuntu for the past two years, and has ports wide open to the net. Fortunately I had already disabled CGI access in Apache as bots were trying to exploit vulns, and Sugar wasn’t using CGI anyway, but this bug still scared the crap out of me.

So I read some blogs and checked out my system, sure enough the command below revealed it was vulnerable:

$ env x='() { :;}; echo “vulnerable”‘ bash -c ‘echo “test”‘
vulnerable
test

The fact that the command managed to print the word “vulnerable” is the red flag.

Fortunately, updating BASH in my case was quite painless:

$ sudo apt-get update
[output snipped]
Fetched 3,399 kB in 4s (680 kB/s)
Reading package lists… Done

$ sudo apt-get install bash
Reading package lists… Done
Building dependency tree
Reading state information… Done
Suggested packages:
  bash-doc
The following packages will be upgraded:
  bash
1 upgraded, 0 newly installed, 0 to remove and 344 not upgraded.
Need to get 616 kB of archives.
After this operation, 12.3 kB of additional disk space will be used.
Get:1 http://gb.archive.ubuntu.com/ubuntu/ precise-updates/main bash i386 4.2-2ubuntu2.3 [616 kB]
Fetched 616 kB in 0s (1,222 kB/s)
(Reading database … 254702 files and directories currently installed.)
Preparing to replace bash 4.2-2ubuntu2.1 (using …/bash_4.2-2ubuntu2.3_i386.deb) …
Unpacking replacement bash …
Processing triggers for menu …
Processing triggers for man-db …
Setting up bash (4.2-2ubuntu2.3) …
update-alternatives: using /usr/share/man/man7/bash-builtins.7.gz to provide /usr/share/man/man7/builtins.7.gz (builtins.7.gz) in auto mode.
Processing triggers for menu …

$ env x='() { :;}; echo “vulnerable”‘ bash -c ‘echo “test”‘

bash: warning: x: ignoring function definition attempt
bash: error importing function definition for `x’
test

The word “vulnerable” is no longer printed so it seems that I’m okay now.

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Have you noticed how slow or laggy Google Chrome is now?

A recent update to Google Chrome (one of these versions seems to be the culprit… 35/36/37) seems to have caused some unintended side-effects. I noticed that it is now really slow when typing text into a web form, and selecting text is also quite tricky as the text selection “block” doesn’t seem to fill in your selection right up to the cursor, but only completes when you click CTRL/C. Basically it is a right royal pain to use and had me briefly switching back to Firefox (I forgot how bad it was, couldn’t even do print to PDF without having to install some dodgy plug-in).

Anyway, I did actually manage to downgrade Chrome to v34 and all was fine for a while until I had to reboot my laptop, whence Chrome automatically updated itself to the latest version and the problem came back.

Now I think I have managed to find the solution, disable “hardware acceleration”. There are those nerdy settings under chrome://flags/, but you can do it easier than that.

Go to “Settings” on the Chrome menu…

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Scroll to the bottom and select “Show advanced settings”:

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Scroll to the bottom and deselect “Use hardware acceleration…”

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I also disabled “Continue running background apps…”

Click on “restart” and it seemed to fix my problem. Let me know in the comments if it worked for you.

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Generating VAT invoices for Skype

Skype, in their infinite wisdom, have decided to remove the ability to download VAT invoices – this makes it tricky for those of us who want to claim back the VAT or use our personal Skype accounts and submit monthly expense receipts to our employers to cover the cost of using this service.

Fortunately a bright spark on the Skype community forums has found a way to generate invoices by modifying one of the URL’s as follows:

  1. Log into the Skype web site and find the purchase history record you want an invoice for.
  2. At the end of the URL, add the following (excluding quotes) ‘/invoice?regenerate=true’

 

 

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More Ant words

Air-be-blane – Aeroplane

Eb-be-gopter – Helicopter

Brink – Drink

Breen – Green

It not working Daddy

It broken

Boo-gumber – Cucumber

Mar-toe – Tomato

Yesssssss

Not binished – finished

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I made it onto the front page of CircleID today!

With all the fuss over the recent DDoS attack against Spamhaus, I wrote a blog article for our web site. I was interested because it used a DNS Reflective Amplification attack, which is something I have been warning about for years (and wrote about 4 years ago on “The Register”).

Digging a bit deeper, I discovered that IP addresses on my local ISP subnet were acting as open DNS resolvers, leading me to conclude that this is a pretty common state of affairs. As open DNS resolvers are a key component of this type of attack, I thought I would submit an article to CircleID – a community of like-minded nerds – highlighting how easily I found an open resolver on an IP address “near” me and challenging others to do the same.

It’s my first posting for CircleID but it has been up there all day on the front page, so I wanted to do a screen grab for posterity so I can come back here in the future to show my kids that I was famous, in a nerdy kind of way!

Click on the image below to go to the article in question…

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My new (old) Speccy – Does it work?

The answer is yes, and no!

I had no problem tuning my LCD TV into the Spectrum’s UHF signal (my TV has an old analogue tuner as well as DVB-T)…

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Unfortunately some of the keys do not work, specifically q, w, e and b, n, m and symbol shift. Sad smile

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A quick look under the hood again, and indeed I can see that at least one of the strips in the right ribbon cable has a break in it. New keyboard membranes seem to be about £10, so I may try and fix it or even see if I can pick up another Speccy for less.

All good fun!

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My new (old) Speccy – First look

So, as part of my 8 bit Mid-life crisis, I bought this 48K Sinclair Spectrum off ebay:

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Listed as untested but was working last time it was used (probably 30 years ago!). Anyway, bugger it, I went for it and won it.

So, this is what arrived a few days later…

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Box a bit battered, but I’m more interested in what’s inside…

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Ok, so no polystyrene packaging, and the Spectrum is a little tatty, so can’t really sell this on in the future as a collectable, the manual is present though. Let’s take a closer look…

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The keys look quite light and grey in this pic but that is the flash, in reality the colour is quite dark, this is definitely not a rare issue 1 Spectrum. It is a bit battered and dented, a big dent between E, R, D and F, hope these keys still work. I think the dent may be due to the power plug on the PSU as the whole lot really wasn’t packed very well. Sad smile The metal cover is peeling away in the top left hand corner (you can see the 1 key is almost flush with the cover where it is lifting up). It does look like someone has tried to peel the metal cover off, maybe they have replaced the keyboard membrane.

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One of the feet is missing, not a big deal, serial no. is 001-318623, looking at the serial number database here it’s looking like a relatively early one.

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Ok, so now if I remember, I had an issue 3 Spectrum, which had a heatsink across the edge connector and was viewable from this angle. There is no heatsink on this one so I reckon it is probably an issue 2 Spectrum. There’s a good article here that explains the differences between the different issues.

Ok let’s take a peek inside, but being careful not to break the keyboard ribbon connectors:

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A-ha, (my favourite 80’s pop group by the way), see the transistor mounted across the CPU, this is definitely looking like an issue 2 Speccy…

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Indeed, zigzag heatsink and here is confirmation, “ISSUE TWO”. So this Speccy is actually older and rarer than the one I had as a kid. Apparently there were about 60,000 issue 1’s produced, approx. 500,000 issue 2’s but over 3 million issue 3’s. I am so used to looking at modern surface mount PCB’s these days that it is quite refreshing to see a board festooned with traditional resistors, diodes, capacitors and potentiometers, looks really old school! Just look at all those old resistors!

Now, does it actually work…?

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