Cupfighter.net

A few days ago while starting TortoiseSVN it prompted me to update to version 1.7

After I updated to version 1.7. I could not connect to our internal repository anymore. The connection failed with the following error: SSL error: sslv3 alert certificate unkown.

SSL error: sslv3 alert certificate unknown

Our internal respoitory is secured with a certificated issued by our internal CA infrastructure.

Root CA

|
v

Intermediate Certificate

|
v

Repository certificate

Surfing to the svn repository does not produce an error, so the certificate chain is fine. At first I figured that Tortoise was using its own certificate store, but it turns out that Tortoise does use the Windows Root CA store, so there is no need to add the Root CA.

After some more investigation we found out that Tortoise does use the Windows Root CA store to validate the certificate chain, but does not use the Intermediate CA store to complete the certificate chain, like windows does. Since all our client machines have the intermediate certificate in the Intermediate CA store we never noticed that the certificates offered by apache were not chained. After chaining the repository certificate with the intermediate certificate Tortoise was able to talk to the repository again.

To “Untrust” the DigiNotar certificates on Windows 2003/XP without installing the MS patch,
you can add the Certificate “Blobs” to the following Certificate Store in the registry “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\Disallowed\Certificates”
<Name>Blob</Name><Type>REG_BINARY</Type>

You can find the “Blob” values on a patched system (see attached link).

These are all the current Certificates in Internet Explorer (including known fraudulent and new DigiNotar):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SystemCertificates\Disallowed\Certificates
\1916A2AF346D399F50313C393200F14140456616
\2B84BFBB34EE2EF949FE1CBE30AA026416EB2216
\305F8BD17AA2CBC483A4C41B19A39A0C75DA39D6
\367D4B3B4FCBBC0B767B2EC0CDB2A36EAB71A4EB
\40AA38731BD189F9CDB5B9DC35E2136F38777AF4
\43D9BCB568E039D073A74A71D8511F7476089CC3
\471C949A8143DB5AD5CDF1C972864A2504FA23C9
\5DE83EE82AC5090AEA9D6AC4E7A6E213F946E179
\61793FCBFA4F9008309BBA5FF12D2CB29CD4151A
\637162CC59A3A1E25956FA5FA8F60D2E1C52EAC6
\63FEAE960BAA91E343CE2BD8B71798C76BDB77D0
\6431723036FD26DEA502792FA595922493030F97
\7D7F4414CCEF168ADF6BF40753B5BECD78375931
\80962AE4D6C5B442894E95A13E4A699E07D694CF
\86E817C81A5CA672FE000F36F878C19518D6F844
\9845A431D51959CAF225322B4A4FE9F223CE6D15
\B533345D06F64516403C00DA03187D3BFEF59156
\B86E791620F759F17B8D25E38CA8BE32E7D5EAC2
\C060ED44CBD881BD0EF86C0BA287DDCF8167478C
\CEA586B2CE593EC7D939898337C57814708AB2BE
\D018B62DC518907247DF50925BB09ACF4A5CB3AD
\F8A54E03AADC5692B850496A4C4630FFEAA29D83

After that you can remove DigiNotar from the Trusted Root Certification Authorities store:

certutil -delstore authroot “c0 60 ed 44 cb d8 81 bd 0e f8 6c 0b a2 87 dd cf 81 67 47 8c”
certutil -delstore authroot “43 d9 bc b5 68 e0 39 d0 73 a7 4a 71 d8 51 1f 74 76 08 9c c3”

On Windows 2008 and newer you have a nifty option in Group Policy:
\Computer Configuration\Policies\Windows Settings\Public Key Policies\Untrusted Certificates

Install the patch on a (local) machine and export the certificates from your “Untrusted Publishers” store as DER encoded, you can import the DER files in the GPO.

Here is the registry hive export from a patched machine, including all certificates and blobs.

cheers,
Matthijs

This post is a reply to this blog post by Jason Kendall.

It all started with this cartoon:

This cartoon basically started a hype about how XKCD was getting “it”. Jason posted a blog post stating that he did not agree with XKCD since:

• While four words in theory have 44 bits of entropy (2⁴⁴), it is actually 250,000 to the power of 4 (250,000⁴) since English only has 4about 250,000 words
• Most people actually would use three words, giving 15,625,000,000,000,000 combinations
• Most people know even less then 250,000 words

So what is my take on this? The key to “it” is at the bottom of the cartoon:

“Through 20 years of effort, we’ve successfully trained everyone to use passwords that are hard for humans to remember, but easy for computers to guess”

This is really the “it” XKCD does get.

So why do we use password policies in the first place? What problem are we trying to tackle?

First of all we are trying to tackle the problem that users are very bad a picking good password without guidance. This tweet illustrates that: Read more…

Phone Bill a CC NC ND image from Nikita Kashner's Flickr stream

By Darren Anstee of Arbor Networks

Why is it a good idea to us flow information?

• You don’t need to invest in new equipment to get flow information
• It can be used to detect malware infected hosts, DDoS, zero-day exploits, attack and abuse
• Network flows information is generated regardless if there was symmetric or a-symmetic routing

Network flow information is like a phone bill, you cannot tell what has been said, but you can use it to prove who talked to who.

So what does a flow record contain?

• Source IP address
• Destination IP address
• Source port
• Destination port
• Input IfIndex
• Protocol
• Type of Service
• packet count
• Byte count
• First packet time
• Last packet time
• Output ifIndex
• Etc…

Read more…

Black Skimmer Rynchops niger Skimming a cc by image from marlin harm's Flick stream

By Adam Laurie and Daniele Bianco

Slides on the HitB Materials page.

So what is EMV it stand for Europay, Mastercard and Vista and is a new security statndard for credit cards.With the introduction of EMV the liabiliy moved from the merchant to the cardholder because fraud is thought to be unlikely.  However EMV has allready been proven to be broken. E.g. Murdoch et. al. have proven that it is possible to use a stolen card without knowing the PIN.

This talk focuses  on the ability to still skim a EMV credit card, without reading the magstripe (which is very often still present).

Skimming a chip card may be more interesting because the user cannot see the interface and thus cannot detect the skimmer. The time effort to install a smartcard skimmer is quite small.

The industry perceives these tools as complex, but that is not true. Devices are small, easy to install and hard to detect.

It is possible to clone the track 1 and track 2 magnetic stripe data from publicly readable data of EMV chip. Luckily not all EMS cards support this.

So magnetic stripe data can be stolen and a stolen card van be used without a PIN, but is it possible to do PIN and magnetic stripe harvesting with EMV cards.

Read more…

Steve Jobs for Fortune magazine a cc nc nd image from tsevis's Flick stream

By Jean-Baptiste Bédrune and Jean Sigwald

Slides on the HitB Materials page.

This talk is about data security and the iPhone. Almost all iPhone like deices (excluding the iPad2 for the moment) can book usigned code when they are in recovery mode. It is also possible to create acustom ram disk, thee are techniques used by jailbreakers and phone forensics people.

Data in the iPhone is encrypted with either the UID (unique iPhone key) or GID (key unique to each model).

In the iPhone (iOS < 4) the UID key was only used  to facilitate fast wipe (change key, cannot read flash anymore), it did not provide data security. The iPhone 4 was designed with data security in mind. Jean and Jean demonstrate the tools they wrote to get around the data protection of iOS 4

Because the unlock code is used for data security data can be set to be only available when:

• The Phone is unlocked
• After the phone is unlocked for the first time
• Always

In iOS 4 there is an escrow key which allows MobileMe and iTunes to access the phone for backup or passcode reset without unlocking the phone.

The first tool that they developed and demonstrated was the keyChainViewer which can be used to view the contents of keyChain, but not the keys.

Using the built in iOS functions (that use the passwcode) you can actually bruto force the passcode of the phone with a small application on the phone. If you boot the phone from a ram disc you can do this without knowing the passcode. Using the brute forced passcode the keyChain can be read and decrypted.

Next tools where demoed to browse the encrypted filesystem and to decrypt iTunes backup files.

Conclusion of the researchers:

• iOS4 offers far better protection then iOS3
• Mail files (with the exception of exchange) are protected by the passcode this offers additional protection, but it can be obtained if you have the phone

Tools are available on http://code.google.com/p/iphone-dataprotection/

About Jean-Baptiste Bédrune

Jean-Baptiste works at the Software security R&D team at Sogeti for 4 years. His domains of research include code (un)protection, audit of DRM solutions, applied cryptography, reverse engineering on embedded devices and distributed computing. Jean joined Sogeti in early 2010. His research topics include reverse engineering, embedded devices and smartphones security.

About Jean Sigwald

Jean Sigwald is a security researcher working at Sogeti ESEC R&D lab. His research is mainly focused on smartphones security and the services offered by the network operators.

Bad day at the office a cc nc ND iamge from Roger Smith's Flick stream

By Itzik Kotler

Slides on the HitB Materials page.

Itzik start his presentation that writing StuxNet for a company is much less hard then writing one for a nuclear reactor. Stuxnet is interesting in that it is a purely software based attack that had a real hardware based effect.

So can software damage hardware? Yes it can:

• Software controls hardware ad can make it perform damaging hardware
• Software can damage software that runs hardware
• Software runs hardware and can make this hardware take an action that damages other hardware

So what is PDOS (Permanent Denial of Service)? Damaging hardware so bad that it needs to be replace or reinstalled.

Users the brick their phone when they try to jailbreak it are basically causing a self inflicted PDoS.

So who would do it and why?

Read more…

Florida Fragments a cc nc sa by image from Merrick Brown's Flickr stream

By Elena Kropochkina and Joffrey Czarny

Slides on the HitB Materials page.

Lots of Webshells used by pentesters to get access to the systems are detected by conventional security products like anti-virus, IPS and WAF. In stead of building a new websheel for each assignment the presenters tried to work towards a framework for webshells, that was modular and added obfuscation as a protection against AV/IPS/WAF.

But if you want to build a webshell framework you need to know what is out there. Most webservers on the internet are dominantly Apache, IIS and Weblogic. Pentesters are most in need of Webshells based on ASP, PHP and Java shells as it is heavily used for intranet applications.

The presenters gave an overview of the webshels out there for webshells for Linux, MySQL, PHP, JSP, ASP. Many of the common shells have high detection rates on the most common anti-virus platforms.

Even tough there are some webshells that are nearly complete in features and others that are not detected by Anti-Virus there isn’t one that is both.

There are a few ways to get around anti-virus encoding, obfuscation and encryption. There are common tools available to obfuscation for different languages like PHP, VBScript and Java. Obfuscation tools make reading the code harder, but are analysis is often still possible.

Read more…

By Don A. Bailey

Slides on the HitB Materials page.

Don’s talk focuses about devices that are designed to track your assets or loved one., specifically the Zoombak who’s biggest selling point is that you can use it to definitely know where your kids are. Zoombak really took off after it was endorsed by TV personality Oprah.

A Zoombak devices basically consist of a GSM module and a MicroController. These two do not share any memory, but talk to each other over a serial channel using AT commands.

On of the first flaws in the Zoombak is that the GSM module can only talk using the decommissioned and broken A5/2 algorithm. A5/2 is so weak that it can be cracked in real time using PC hardware, but Don didn’t use this eakness to attack the device.

Because being on the GSM network all the time is too expensive the Zoombak device works differently. If you want to know the location of the device you send it an SMS, the SMS is polled from the SIM by the Micro Controller and acts on this command, e.g. by sending the location of the device to a website over the GPRS network.

Read more…

For Heat a CC-NC-ND image from ailatan's Flickr stream

By Xavier Mertens

Managing security events from you network. It is often perceived as boring. There is a lot of information and lots of tools. Additionally log formats are not standardized.

There are also economic issues, uptime often takes precedence over uptime, it takes time, staff may be reduced and it not a revenue generating activity.

Additionally there are legal issues, these issues center around privacy and have to be checked against local law.

Managing security logs is a layered approach:

1. Log collection
2. Normalization
3. Storage
4. Search
5. Reporting
6. Correlation

Correlation can be used to give events more meaning. This can be done with external sources like vulnerability information, but also with internal sources like e.g. badge swipes or geo-location. Read more…