Security

Data Privacy issue: Your Android phone might leak your IMEI…

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Just played around with a new home router and noticed that my HTC Desire S Android phone sends the following hostname when requesting an IP address with DHCP in a wireless network:

Android_3567080XXXXXXXX

Why is this is a problem? Because the trailing part of that hostname is your IMEI, which is a unique number identifying your device. It’s normally only seen on radio-network level, so can normally be considered “private” (because your operator can’t disclose it to anyone).

The IMEI also contains a component called “TAC” (type allocation code) which identified the exact handset model you have.

So if you regularly visit Internet cafes or the like, these guys know how often and when you are there.

Please let me know whether you consider this a problem or not — I do think it is one.

Computers, Debian, Linux, Security

Integrate “AVG Anti-Virus Free Edition” into Exim with ExiScan patch

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If you would like to integrate “AVG Anti-Virus Free Edition” into Exim, using the ExiScan patch, this is actually quite easy.

Just insert the following fragment into your Exim config:

  # Reject virus infected messages.
  # Add message to implicit X-ACL-Warn: header
  warn  message         = This message contains malware ($malware_name)
        set acl_m0      = cmdline:\
                          /usr/bin/avgscan --arc %s; echo -e \N"\navg_retval $?"\N:\
                          avg_retval 5:\
                          \NVirus identified *(.*)$\N
        malware         = *
        log_message     = This message contains malware (avg:$malware_name)

Let me know if this works for you — I hacked this up quite quickly, but it seems to do its job…

Datenschutz, Social Networks

How to “demilitarize” the Facebook “Like” button on web pages…

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If you’re concerned about privacy you might be worried by the “Like” button found on lots of web sites. If you’re logged onto Facebook while you visit such pages Facebook knows that you were there…

So what can you do to disable that worrysome behavior? Simple. Use Firefox and the NoScript extension. Open the NoScript “Options” dialog, switch to the “Advanced” tab and then the “ABE” sub-tab, enable the ABE feature by activating the “Enable ABE” checkbox, and add the following snippet to the “USER” ruleset:

# This one allows Facebook scripts and objects to be included only
# from Facebook pages
Site .facebook.com .fbcdn.net
Accept from .facebook.com .fbcdn.net
Deny INCLUSION(SCRIPT, OBJ, SUBDOC)

Presto! You no longer need to worry about Facebook spying on you on “foreign” pages… 🙂

Windows

How Apple’s Bonjour service may break your net config…

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Suddenly my brand-new, only a couple of days old Windows 7 installation had an odd problem: After a system boot or restart, networking would be broken in a way that hosts in the Internet could not be reached.

I investigated the problem and noticed that my Ethernet adapter had two default gateways assigned, while the first was 0.0.0.0:

C:\Users\rabe>ipconfig /all
[...]
Ethernet adapter Local Area Connection:
[...]
   Default Gateway . . . . . . . . . : 0.0.0.0
                                       192.168.2.1

I googled for this problem and found some hint that pointed toward’s Apple’s Bonjour service. Supposedly it sometimes starts up before networking is fully up, and in consequence assigns the invalid default gateway. The advice given there to solve the problem was to completely disable this service.

While I currently don’t need this service, I didn’t want to use this “brutal” approach, so what I did was switch the service to start up as Automatic (Delayed Start) as opposed to Automatic (which causes the service to start as early as possible).

And this indeed did the trick — I don’t have these annoying networking problems anymore. 🙂

Update: To correct the name in the “Services” application which will often be Id_String2.6844F930_1628_4223_B5CC_5BB94B879762 you can use a command sequence as follows (your path to mDNSResponder.exe may vary):

"C:\Program Files\Bonjour\mDNSResponder.exe" -remove
"C:\Program Files\Bonjour\mDNSResponder.exe" -install
Mac

How to “clone” Finder windows under Mac OS X Snow Leopard…

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I’m now using Mac OS X since 1.5 years, and something that I always wanted to be able to do is to quickly open another Finder window that shows the same path as another one.

Today I discovered how to do this (not exactly obvious, if you ask me!), and here’s how…

Press Cmd-N to open a new window. With the new window being active, click Cmd-Shift-G to open the “Go to the folder” prompt. Press BkSpc to clear the prefilled content. Now activate the window that you would like to “clone.” Click-drag the Folder symbol in the title bar and drag it into the “Go to the folder” prompt. Click “Go” or press Return.

Presto! You cloned your original Finder window.

If you know more hints like this, please do post them here!

Vacation

MasterCard discriminates European cardholders

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A couple of days ago, I booked a journey to Kuala Lumpur and Bali for my wife and me. When it came to paying the travel agent advised me that there would be a surcharge of 0.3% imposed by the tour operator when you pay with credit card — independent of which brand your credit card is.

I was pretty outraged because of the surcharge, because until then I was pretty sure that this kind of charges were expressly forbidden by card acquirers (an “acquirer” is the party which acquires the transacations of the merchant).

Therefore I visited MasterCard’s website in order to investigate their acceptance procedures. I found something very interesting in the MasterCard rules dated 2009-11-06.

In article 5.9.2. it says about “Charges to cardholders:”

A Merchant must not directly or indirectly require any Cardholder to pay a surcharge or any part of any Merchant discount or any contemporaneous finance charge in connection with a Transaction.

Duh!

When I continued to read I found a section “10 Europe Region Rules” where it said the following in “10A.3 Charges to Cardholders:”

Rule 5.9.2 does not apply in the European Economic Area.

So, why is this? Why does MasterCard reserve the right to discriminate their European cardholders compared to their US cardholders? “What have we done to deserve this?”

To Meier’s Weltreisen, the tour operator: Instead of adding surcharges to customers who pay using a credit card (and that will be the absolute majority of all customers), you should recalculate your prices and refrain from playing such dirty tricks.

Computers

Thunderbird 3.0 Upgrade: Stored Passwords “lost”

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I recently installed the upgrade to Thunderbird 3.0 on our main PC. In my account, all was fine afterwards, but my wife had a very strange problem: All previously stored passwords seemed lost. TB 3.0 asked for the passwords of all accounts that she had, both IMAP and NNTP. When I started TB 2.0 (which I reinstalled for investigating this issue), all was fine again — apart from the password for the NNTP account, which was incorrect or missing, so I entered it again.

I noticed that now that TB 3.0 was installed, there was a file signons.sqlite in the Profiles folder in addition to the well-known signons3.txt file. I figured that the SQLite file was probably the new password store, which was migrated from the pre-3.0 password store in the TXT file. I further figured that during the migration something probably went wrong (eventually the missing/incorrect/corrupt NNTP password?), so I removed the SQLite file and started TB 3.0 up again. Upon starting up, it recreated the SQLite file, and this time all worked well.

So, if you folks have a similar problem, try the approach I described here. It should not be risky at all, since the TXT will always be the “master” file when migrating from 2.0 to 3.0, so removing the SQLite file will have it re-created again upon next startup.

Computers, Mac, WTF

Snow Leopard’s “Disk Utility” can’t create encrypted image

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Two months or so I ordered the Snow Leopard DVD for my Macbook Pro. Finally I had the time to perform the upgrade from Leopard. Before actually doing so, I tried to create a disk image of my current Leopard installation. So I booted the Snow Leopard DVD and ran “Disk Utility” from it. Because the target of that disk image was an external hard drive shared by my team, I wanted to create an encrypted image.

Regardless of whether I selected “128-Bit AES” or “256-Bit AES” as an encryption method, I immediately received the following error message on screen:

Unable to create "Macintosh HD.dmg" (Cannot allocate memory)

What is this trying to tell me? No space on hard drive? Impossible, since the external hard drive is a 2 TB empty drive. Moreover, “memory” usually refers to “main memory”, or “RAM.” So is Disk Utility actually trying to read the whole 200 GB hard drive into the RAM, then encrypting it, and then creating the disk image from it?! I can’t believe that anyone would be that stupid to design a disk imaging program like this…

I finally changed the image format to “Compressed”, and presto, it worked!

Anyway, why, oh why is it so hard to generate “user friendly” error messages? And why does this happen under Mac OS X of all operating systems, supposedly being the “user friendliest” OS in the universe?

This is not the first time I receive such useless error messages in OS X. Hey Apple, care to finally make your homework???

Travel

Isch nix versteh’n… (Miles & More)

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Kürzlich war ich auf einer Geschäftsreise in Schweden. Die Flüge (insg. vier Teilstrecken) hatten wir über Lufthansa gebucht. Durchgeführt wurden sie aber teilweise durch die SAS bzw. Cimber Air.

Nun wollte ich mir diese Flüge nachträglich auf meinem Miles & More-Konto gutschreiben lassen und kontaktierte daher Lufthansa. Als “Antwort” auf meine Bitte um Prüfung, ob und wenn ja welche Flüge angerechnet werden könnten, erhielt ich ein Schreiben mit folgendem Inhalt:

Ihre Meilen erfassen wir immer unter der Flugnummer des Partners, der den Flug durchgeführt hat (Operating Carrier). Handelt es sich um einen Partner der Star Alliance, schreiben wir auch Statusmeilen gut. Nimmt die entsprechende Airline nicht an Miles & More teil, können keine Meilen berücksichtigt werden. Dies ist unabhängig davon, welche Flugnummer auf Ihrem Ticket vermerkt ist.

Nach diesem Schreiben war ich so schlau wie vorher — können nun Flüge angerechnet werden oder nicht? Wenn ja, wie viele?

Continue reading Isch nix versteh’n… (Miles & More) →

Networking, Windows

Cisco VPN install nightmare on Vista

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Here’s another Cisco VPN client nightmare for you:

The old 4.9.x.x Cisco VPN client does’t run under Vista anymore. So I downloaded the most current version our organization has available, 5.0.05.290. I started the installer and pretty quickly received an error message that simply said: “Internal Error 2738″.

I thought maybe the install file was corrupt, so I redownloaded it — same error.

Now I read the readme file (which I normally don’t do ;-)) It said you need a Microsoft hotfix in order to be able to install the VPN client. So I downloaded that one as well and retried the installation after rebooting the machine — same error message agin.

Damn!

So I googled for this problem and quickly came across this website — which indeed fixed the problem for me.

Thanks, Microsoft, for making such a lousy job of not registering said DLL. And thanks, Cisco, for not pointing your customers to this problem.

Gaaaawd, how I hate monopolies…

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