What is BurpSuite? Burp Suite is a Java based Web Penetration Testing framework. It has become an industry standard suite of tools used by information security professionals. Burp Suite helps you identify vulnerabilities and verify attack vectors that are affecting web applications. Because of its popularity and breadth as well as depth of features, we have created this useful page as a collection of Burp Suite knowledge and information.
In its simplest form, Burp Suite can be classified as an Interception Proxy. While browsing their target application, a penetration tester can configure their internet browser to route traffic through the Burp Suite proxy server. Burp Suite then acts as a (sort of) Man In The Middle by capturing and analyzing each request to and from the target web application so that they can be analyzed.
Everyone has their favorite security tools, but when it comes to mobile and web applications I've always found myself looking BurpSuite . It always seems to have everything I need and for folks just getting started with web application testing it can be a challenge putting all of the pieces together. I'm just going to go through the installation to paint a good picture of how to get it up quickly.
BurpSuite is freely available with everything you need to get started and when you're ready to cut the leash, the professional version has some handy tools that can make the whole process a little bit easier. I'll also go through how to install FoxyProxy which makes it much easier to change your proxy setup, but we'll get into that a little later.
Requirements and assumptions:
Mozilla Firefox 3.1 or Later Knowledge of Firefox Add-ons and installation The Java Runtime Environment installed
Download BurpSuite from http://portswigger.net/burp/download.htmland make a note of where you save it.
on for Firefox from https://addons.mozilla.org/en-US/firefox/addon/foxyproxy-standard/
If this is your first time running the JAR file, it may take a minute or two to load, so be patient and wait.
Video for setup and installation.
You need to install compatible version of java , So that you can run BurpSuite.
Bob was tasked to break into XYZcorporation, so he pulled up the facility on google maps to see what the layout was. He was looking for any possible entry paths into the company headquarters. Online maps showed that the whole facility was surrounded by a security access gate. Not much else could be determined remotely so bob decided to take a drive to the facility and get a closer look.
Bob parked down the street in view of the entry gate. Upon arrival he noted the gate was un-manned and cars were rolling up to the gate typing in an access code or simply driving up to the gate as it opening automatically.Interestingly there was some kind of wireless technology in use.
How do we go from watching a car go through a gate, to having a physical device that opens the gate?
We will take a look at reversing a signal from an actual gate to program a remote with the proper RF signal.Learning how to perform these steps manually to get a better understanding of how RF remotes work in conjunction with automating processes with RFCrack.
In the the previous blogs, we sniffed signals and replayed them to perform actions. In this blog we are going to take a look at a signal and reverse it to create a physical device that will act as a replacement for the original device. Depending on the scenario this may be a better approach if you plan to enter the facility off hours when there is no signal to capture or you don't want to look suspicious.
Recon:
Lets first use the scanning functionality in RFCrack to find known frequencies. Weneed to understand the frequencies that gates usually use. This way we can set our scanner to a limited number of frequencies to rotate through. The smaller rage of frequencies used will provide a better chance of capturing a signal when a car opens the target gate. This would be beneficial if the scanning device is left unattended within a dropbox created with something like a Kali on a Raspberry Pi. One could access it from a good distance away by setting up a wifi hotspot or cellular connection.
Based on research remotes tend to use 315Mhz, 390Mhz, 433Mhz and a few other frequencies. So in our case we will start up RFCrack on those likely used frequencies and just let it run. We can also look up the FCID of our clicker to see what Frequencies manufactures are using. Although not standardized, similar technologies tend to use similar configurations. Below is from the data sheet located at https://fccid.io/HBW7922/Test-Report/test-report-1755584 which indicates that if this gate is compatible with a universal remote it should be using the 300,310, 315, 372, 390 Frequencies. Most notably the 310, 315 and 390 as the others are only on a couple configurations.
RFCrack Scanning:
Since the most used ranges are 310, 315, 390 within our universal clicker, lets set RFCrack scanner to rotate through those and scan for signals.If a number of cars go through the gate and there are no captures we can adjust the scanner later over our wifi connection from a distance.
Currently Scanning: 433000000 To cancel hit enter and wait a few seconds
Example of logging output:
From the above output you will see that a frequency was found on 390. However, if you had left this running for a few hours you could easily see all of the output in the log file located in your RFCrack/scanning_logs directory.For example the following captures were found in the log file in an easily parseable format:
Analyzing the signal to determine toggle switches:
Ok sweet, now we have a valid signal which will open the gate. Of course we could just replay this and open the gate, but we are going to create a physical device we can pass along to whoever needs entry regardless if they understand RF. No need to fumble around with a computer and look suspicious.Also replaying a signal with RFCrack is just to easy, nothing new to learn taking the easy route.
The first thing we are going to do is graph the capture and take a look at the wave pattern it creates. This can give us a lot of clues that might prove beneficial in figuring out the toggle switch pattern found in remotes. There are a few ways we can do this. If you don't have a yardstick at home you can capture the initial signal with your cheap RTL-SDR dongle as we did in the first RF blog. We could then open it in audacity. This signal is shown below.
Let RFCrack Plot the Signal For you:
The other option is let RFCrack help you out by taking a signal from the log output above and let RFCrack plot it for you.This saves time and allows you to use only one piece of hardware for all of the work.This can easily be done with the following command:
From the graph output we see 2 distinct crest lengths and some junk at either end we can throw away. These 2 unique crests correspond to our toggle switch positions of up/down giving us the following 2 possible scenarios using a 9 toggle switch remote based on the 9 crests above:
Possible toggle switch scenarios:
down down up up up down down down down
up up down down down up up up up
Configuring a remote:
Proper toggle switch configuration allows us to program a universal remote that sends a signal to the gate. However even with the proper toggle switch configuration the remote has many different signals it sends based on the manufacturer or type of signal.In order to figure out which configuration the gate is using without physically watching the gate open, we will rely on local signal analysis/comparison.
Programming a remote is done by clicking the device with the proper toggle switch configuration until the gate opens and the correct manufacturer is configured. Since we don't have access to the gate after capturing the initial signal we will instead compare each signal from he remote to the original captured signal.
Comparing Signals:
This can be done a few ways, one way is to use an RTLSDR and capture all of the presses followed by visually comparing the output in audacity. Instead I prefer to use one tool and automate this process with RFCrack so that on each click of the device we can compare a signal with the original capture. Since there are multiple signals sent with each click it will analyze all of them and provide a percent likelihood of match of all the signals in that click followed by a comparing the highest % match graph for visual confirmation. If you are seeing a 80-90% match you should have the correct signal match.
Note:Not every click will show output as some clicks will be on different frequencies, these don't matter since our recon confirmed the gate is communicating on 390Mhz.
In order to analyze the signals in real time you will need to open up your clicker and set the proper toggle switch settings followed by setting up a sniffer and live analysis with RFCrack:
Open up 2 terminals and use the following commands:
#Setup a sniffer on 390mhz Setup sniffer:python RFCrack.py -k -c -f 390000000.
#Monitor the log file, and provide the gates original signal Setup Analysis: python RFCrack.py -c -u 1f0fffe0fffc01ff803ff007fe0fffc1fff83fff07ffe0007c -n.
Cmd switches used
-k = known frequency
-c = compare mode
-f = frequency
-n = no yardstick needed for analysis
Make sure your remote is configured for one of the possible toggle configurations determined above. In the below example I am using the first configuration, any extra toggles left in the down position: (down down up up up down down down down)
Analyze Your Clicks:
Now with the two terminals open and running click the reset switch to the bottom left and hold till it flashes. Then keep clicking the left button and viewing the output in the sniffing analysis terminal which will provide the comparisons as graphs are loaded to validate the output.If you click the device and no output is seen, all that means is that the device is communicating on a frequency which we are not listening on.We don't care about those signals since they don't pertain to our target.
At around the 11th click you will see high likelihood of a match and a graph which is near identical. A few click outputs are shown below with the graph from the last output with a 97% match.It will always graph the highest percentage within a click.Sometimes there will be blank graphs when the data is wacky and doesn't work so well. This is fine since we don't care about wacky data.
You will notice the previous clicks did not show even close to a match, so its pretty easy to determine which is the right manufacture and setup for your target gate. Now just click the right hand button on the remote and it should be configured with the gates setup even though you are in another location setting up for your test.
For Visual of the last signal comparison go to ./imageOutput/LiveComparison.png
----------Start Signals In Press--------------
Percent Chance of Match for press is: 0.05
Percent Chance of Match for press is: 0.14
Percent Chance of Match for press is: 0.14
Percent Chance of Match for press is: 0.12
----------End Signals In Press------------
For Visual of the last signal comparison go to ./imageOutput/LiveComparison.png
----------Start Signals In Press--------------
Percent Chance of Match for press is: 0.14
Percent Chance of Match for press is: 0.20
Percent Chance of Match for press is: 0.19
Percent Chance of Match for press is: 0.25
----------End Signals In Press------------
For Visual of the last signal comparison go to ./imageOutput/LiveComparison.png
----------Start Signals In Press--------------
Percent Chance of Match for press is: 0.93
Percent Chance of Match for press is: 0.93
Percent Chance of Match for press is: 0.97
Percent Chance of Match for press is: 0.90
Percent Chance of Match for press is: 0.88
Percent Chance of Match for press is: 0.44
----------End Signals In Press------------
For Visual of the last signal comparison go to ./imageOutput/LiveComparison.png
Graph Comparison Output for 97% Match:
Conclusion:
You have now walked through successfully reversing a toggle switch remote for a security gate. You took a raw signal and created a working device using only a Yardstick and RFCrack.This was just a quick tutorial on leveraging the skillsets you gained in previous blogs in order to learn how to analyzeRF signals within embedded devices. There are many scenarios these same techniques could assist in.We also covered a few new features in RF crack regarding logging, graphing and comparing signals.These are just a few of the features which have been added since the initial release. For more info and other features check the wiki.
Mentor classes are special, 10 week-format SANS classroom sessions that give the students time to absorb and master the same material with the guidance of a trained security professional.
Students receive all the same course materials used at SANS conferences and study at a more leisurely pace, so students will have:
Hardcopy set of SANS course books
Mentor Program study materials
Weekly Mentor led sessions
Prior to the weekly Mentor-led classroom sessions, students study SANS course material at their own pace. Each week, students meet with other professionals in their hometown area and the SANS mentor, who leads topical discussions pointing out the most salient features of the weekly material studied, provides hands-on demonstrations, and answer questions. The Mentor's goal is to help student's grasp the more difficult material, master the exercises, demonstrate the tools and prepare for GIAC certification.
On SANS SEC575, we will learn about mobile device infrastructures, policies and management, we will see the security models of the different platforms, like the data storage and file system architecture. We will also see how to unlock, root and jailbreak mobile devices in order to prepare them for data extraction and further testing. In the second half of the course, we will learn how to perform static and dynamic mobile application analysis, the usage of automated application analysis tools and how to manipulate application behavior. Last but not least, we will see how to perform mobile penetration testing that includes fingerprinting mobile devices, wireless network probing and scanning, attacking wireless infrastructures, using network manipulation attacks and attacks against mobile applications and back-end applications.
We found out that in contrast to public knowledge, the Pre-Shared Key (PSK) authentication method in main mode of IKEv1 is susceptible to offline dictionary attacks. This requires only a single active Man-in-the-Middle attack. Thus, if low entropy passwords are used as PSKs, this can easily be broken.
In his blog post, Dennis showed how to attack the public key encryption based authentication methods of IKEv1 (PKE & RPKE) and how to use this attack against IKEv2 signature based authentication method. In this blog post, I will focus on another interesting finding regarding IKEv1 and the Pre-Shared Key authentication.
IPsec and Internet Key Exchange (IKE)
IPsec enables cryptographic protection of IP packets. It is commonly used to build VPNs (Virtual Private Networks). For key establishment, the IKE protocol is used. IKE exists in two versions, each with different modes, different phases, several authentication methods, and configuration options. Therefore, IKE is one of the most complex cryptographic protocols in use.
In version 1 of IKE (IKEv1), four authentication methods are available for Phase 1, in which initial authenticated keying material is established: Two public key encryption based methods, one signature based method, and a PSK (Pre-Shared Key) based method.
The relationship between IKEv1 Phase 1, Phase 2, and IPsec ESP. Multiple simultaneous Phase 2 connections can be established from a single Phase 1 connection. Grey parts are encrypted, either with IKE derived keys (light grey) or with IPsec keys (dark grey). The numbers at the curly brackets denote the number of messages to be exchanged in the protocol.
Pre-Shared Key authentication
As shown above, Pre-Shared Key authentication is one of three authentication methods in IKEv1. The authentication is based on the knowledge of a shared secret string. In reality, this is probably some sort of password.
The IKEv1 handshake for PSK authentication looks like the following (simplified version):
In the first two messages, the session identifier (inside HDR) and the cryptographic algorithms (proposals) are selected by initiator and responder.
In messages 3 and 4, they exchange ephemeral Diffie-Hellman shares and nonces. After that, they compute a key k by using their shared secret (PSK) in a PRF function (e.g. HMAC-SHA1) and the previously exchanged nonces. This key is used to derive additional keys (ka, kd, ke). The key kd is used to compute MACI over the session identifier and the shared diffie-hellman secret gxy. Finally, the key ke is used to encrypt IDI (e.g. IPv4 address of the peer) and MACI.
Weaknesses of PSK authentication
It is well known that the aggressive mode of authentication in combination with PSK is insecure and vulnerable against off-line dictionary attacks, by simply eavesedropping the packets. For example, in strongSwan it is necessary to set the following configuration flag in order to use it:
For the main mode, we found a similar attack when doing some minor additional work. For that, the attacker needs to waits until a peer A (initiator) tries to connect to another peer B (responder). Then, the attacker acts as a man-in-the middle and behaves like the peer B would, but does not forward the packets to B.
From the picture above it should be clear that an attacker who acts as B can compute (gxy) and receives the necessary public values session ID, nI, nR. However, the attacker does not know the PSK. In order to mount a dictionary attack against this value, he uses the nonces, and computes a candidate for k for every entry in the dictionary. It is necessary to make a key derivation for every k with the values of the session identifiers and shared Diffie-Hellmann secret the possible keys ka, kd and ke. Then, the attacker uses ke in order to decrypt the encrypted part of message 5. Due to IDI often being an IP address plus some additional data of the initiator, the attacker can easily determine if the correct PSK has been found.
Who is affected?
This weakness exists in the IKEv1 standard (RFC 2409). Every software or hardware that is compliant to this standard is affected. Therefore, we encourage all vendors, companies, and developers to at least ensure that high-entropy Pre-Shared Keys are used in IKEv1 configurations.
In order to verify the attack, we tested the attack against strongSWAN 5.5.1.
Proof-of-Concept
We have implemented a PoC that runs a dictionary attack against a network capture (pcapng) of a IKEv1 main mode session. As input, it also requires the Diffie-Hellmann secret as described above. You can find the source code at github. We only tested the attack against strongSWAN 5.5.1. If you want to use the PoC against another implementation or session, you have to adjust the idHex value in main.py.
Responsible Disclosure
We reported our findings to the international CERT at July 6th, 2018. We were informed that they contacted over 250 parties about the weakness. The CVE ID for it is CVE-2018-5389 [cert entry].
On August 10th, 2018, we learned that this attack against IKEv1 main mode with PSKs was previously described by David McGrew in his blog post Great Cipher, But Where Did You Get That Key?. We would like to point out that neither we nor the USENIX reviewers nor the CERT were obviously aware of this. On August 14th 2018, Graham Bartlett (Cisco) email us that he presented the weakness of PSK in IKEv2 in several public presentations and in his book. On August 15th 2018, we were informed by Tamir Zegman that John Pliam described the attack on his web page in 1999.
FAQs
Do you have a name, logo, any merchandising for the attack? No.
Have I been attacked? We mentioned above that such an attack would require an active man-in-the-middle attack. In the logs this could look like a failed connection attempt or a session timed out. But this is a rather weak indication and no evidence for an attack.
What should I do? If you do not have the option to switch to authentication with digital signatures, choose a Pre-Shared Key that resists dictionary attacks. If you want to achieve e.g. 128 bits of security, configure a PSK with at least 19 random ASCII characters. And do not use something that can be found in public databases.
Am I safe if I use PSKs with IKEv2? No, interestingly the standard also mentions that IKEv2 does not prevent against off-line dictionary attacks.
What else does the paper contain? The paper contains a lot more details than this blogpost. It explains all authentication methods of IKEv1 and it gives message flow diagrams of the protocol. There, we describe a variant of the attack that uses the Bleichenbacher oracles to forge signatures to target IKEv2.
Hello Everyone, Today I am Going To Write a very interesting post for You ..hope you all find this valuable.. : What is The cost to hire a spy who can able to spy your girlfriend 24X7 days..???? it's around hundreds of dollars Or Sometimes Even Thousands of dollars
But you are on Hacking-News & Tutorials so everything mentioned here is absolutely free. would you be happy if I will show you a Secret Mobile Phone trick by which you can Spy and trace your girlfriend, spouse or anyone's mobile phone 24 X 7 which is absolutely free?The only thing you have to do is send an SMS like SENDCALLLOG To get the call history of your girlfriend's phone.isn't it Sounds Cool...
Without Taking Much Of Your Time… let's Start The trick…
STEP 1: First of all go to android market from your Girlfriend, spouse, friends or anyone's phone which you want to spy or download the app mentioned below.
STEP 2: Search for an android application named "Touch My life "
STEP 3: download and install that application on that phone.
STEP 4: Trick is Over
Now you can able to spy that phone anytime by just sending SMS to that phone.
Now give back that phone to your girlfriend. and whenever you want to spy your girlfriend just send SMS from your phone to your Girlfriend phone Which are mentioned in Touch My Life manage to book.
1) Write "CALL ME BACK" without Quotes and Send it to your girlfriend's mobile number for an Automatic call back from your girlfriend's phone to your phone.
2)Write "VIBRATENSEC 30" without Quotes and send it to your girlfriend's mobile number to Vibrate your Girlfriend's Phone for 30 seconds.You can also change Values from 30 to anything for the desired Vibrate time.
3)Write "DEFRINGTONE" without Quotes and Send it to your girlfriend's mobile number..this will play the default ringtone on your girlfriend's phone.
4)Write "SEND PHOTO youremail@gmail.com" without Quotes and Send it to your girlfriend's mobile number.it will take the photo of the current location of your girlfriend and send it to the email address specified in the SMS as an attachment.it will also send a confirmation message to your number.
5)Write "SENDCALLLOG youremail@gmail.com" without Quotes and Send it to your girlfriend's mobile number ..it will send all the call details like incoming calls, outgoing calls, missed calls to the email address specified in the SMS.
6)Write "SENDCONTACTLIST youremail@gmail.com" without Quotes and Send it to your girlfriend's mobile number ..it will send all the Contact list to the email address specified in the SMS.
So Guys Above all are only some Handy features of touch my life…You can also view more by going to touch my life application and then its manage rules...
Security Assertion Markup Language (SAML) is an XML-based standard commonly used in Web Single Sign-On (SSO) [1]. In SAML, the confidentiality of transferred authentication statements against intermediaries can be provided using XML Encryption [2]. However, implementing XML Encryption in a secure way can be tricky and several attacks on XML Encryption have been identified in the past [3] [4]. Therefore, when auditing a SAML endpoint, one should always consider testing for vulnerabilities in the XML Encryption implementation.
This blog post introduces our latest addition to the SAML Attacker of our BurpSuite extension EsPReSSO: the Encryption Attack tab. The new tab allows for easy manipulation of the encrypted parts within intercepted SAML responses and can, therefore, be used to quickly assess whether the SAML endpoint is vulnerable against certain XML Encryption attacks.
Weaknesses of XML Encryption
Implementations of XML Encryption can be vulnerable to adaptive chosen ciphertext attacks. This is a class of attacks in which the attacker sends a sequence of manipulated ciphertexts to a decryption oracle as a way to gain information about the plaintext content.
Falsely implemented XML Encryption can be broken using:
an attack against the CBC-mode decryption (quite similar to a padding oracle attack) [3] or
a Bleichenbacher attack against the RSA-PKCS#1 encryption of the session key [4].
SAML makes use of XML Encryption and its implementations could, therefore, also be vulnerable to these attacks.
XML Encryption in SAML
To support confidential transmission of sensitive data within the SAML Assertion, assertions can be encrypted using XML Encryption. An EncryptedAssertion is shown in the abridged example below.
The EncryptedAssertion contains an EncryptedData element, which in turn is the parent of the EncryptionMethod, KeyInfo, and CipherData elements. SAML makes use of what is referred to as a hybrid encryption scheme. This is done using a session key which symmetrically encrypts the payload data (the example uses AES-128 in CBC mode), resulting in the ciphertext contained in the EncryptedAssertion/EncryptedData/CipherData/CipherValue child element. The session key itself is encrypted using an asymmetric encryption scheme. In our example, RSA-PKCS#1.5 encryption is used with the public key of the recipient, allowing the contents of the the EncryptedKey child element to be derived from the KeyInfo element.
Encryption Attacker
Our BurpSuite extension EsPReSSO can help detect vulnerable implementations with the newly integrated Encryption Attacker within EsPReSSO's SAML module.
Once a SAML response which contains an EncryptedAssertion has been intercepted, open the SAML tab, select the Attacks pane, and choose Encryption from the dropdown menu. This works in Burp's Proxy, as well as in the Repeater tool, and is depicted below.
As sketched out above, the symmetric session key is encrypted using the recipient's public key. Since the key is public, anybody can use it to encrypt a selected symmetric key and submit a valid encryption of arbitrary messages to the recipient. This is incredibly helpful because it allows us to produce ciphertexts that decrypt the chosen plaintexts. To accomplish this, one can purposefully send invalidly padded messages, or messages containing invalid XML, as a method to trigger and analyze the different reactions of the decryption endpoint (i.e, turning the endpoint into a decryption oracle). To facilitate these investigations, the new Encryption Attacker makes this process dead simple.
The screenshot above shows the essential interface of the new encryption tab: At the top, the certificate used to encrypt the symmetric session key can be pasted into the text field. This field will be pre-filled automatically if the intercepted SAML message includes a certificate in the KeyInfo child element of the EncryptedData element. The Update Certificate checkboxes above the text area can be used to include the certificate in the manipulated SAML message. In the Symmetric Key text field, the hexadecimal value of the symmetric session key can be set. Choose the asymmetric algorithm from the dropdown menu and click Encrypt key -- this will update the corresponding KeyInfo elements of the intercepted SAML message.
The payload in the text area labeled XML data can now be entered. Any update in the XML data field will also be reflected in the hexadecimal representation of the payload (found on right of the XML data field). Note that this is automatically padded to the blocklength required by the symmetric algorithm selected below. However, the payload and the padding can be manually adjusted in the hex editor field.
Eventually, click the Encrypt content button to generate the encrypted payload. This will apply the changes to the intercepted SAML message, and the manipulated message using Burp's Forward or Go button can now be forwarded, as usual.
Probing for Bleichenbacher Oracles
Bleichenbacher's attack against RSA-PKCS1 v1.5 encryption abuses the malleability of RSA to draw conclusions about the plaintext by multiplying the ciphertext with adaptively chosen values, and observing differences in the received responses. If the (error-) responses differ for valid and invalid PKCS1 v1.5 ciphertexts, Bleichenbachers' algorithm can be used to decrypt the ciphertext without knowing the private key [6].
To determine whether or not a SAML endpoint is vulnerable to Bleichenbacher's Attack, we simply need to check if we can distinguish those responses received when submitting ciphertexts that are decrypted into invalidly formatted PKCS1 v1.5 plaintexts, from the responses we receive when sending ciphertexts that are decrypted into validly formatted plaintexts.
Recall that PKCS1 v1.5 mandates a certain format of the encrypted plaintext, namely a concatenation of a BlockType 00 02, a randomized PaddingString (PS) that includes no 00 bytes, a 00 (NULL-byte) as delimiter, and the actual plaintext message. The whole sequence should be equal in size to the modulus of the RSA key used. That is, given the byte length k of the RSA modulus and the message length |m|, PS has the length |PS| = k - 3 - |m|. Furthermore, PKCS1 v1.5 demands that |PS| to be at least eight bytes long [5].
In SAML, the recipient's public key is usually known because it is published in the metadata, or even included in the EncryptedAssertion. For this reason, we do not need to fiddle around with manipulated ciphertexts. Instead, we simply submit a validly formatted RSA-PKCS1 v1.5 encrypted message and an encrypted message which deciphers into an invalidly formatted plaintext. As an example, assume an RSA public key of 2048 bits which we want to use to encrypt a 16 byte session key `01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10` (hexadecimal representation). |PS|$ is $2048/8 - 3 - 16 = 237, so a valid PKCS1 v1.5 plaintext, ready to be encrypted using `AA` for all 237 padding bytes, could look like the listing shown below.
00 02 AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA AA 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10
In the Encryption attack pane of EsPReSSO, ensure that the correct public key certificate has been added to the Certificate field. Insert a valid plaintext, such as the one above, into the Symmetric Key field and select Plain RSA encryption from the Algorithm drop down menu. Click the Encrypt button to compute the RSA transformation and apply the new EncryptedKey element to the intercepted SAML message. Now, submit the message by clicking Burp's Go or Forward button and carefully inspect the response.
Next, repeat the steps outlined above, but this time submit an invalid PKCS1 v1.5 message. For example, consider using an invalid BlockType of `12 34` instead of `00 02`, or replace the `00` delimiter so that the decryptor is unable to determine the actual message after decrypting the ciphertext. If you are able to determine from the recieved responses whether or not the submitted ciphertext decrypted into a valid PKCS1 v1.5 formatted plaintext, chances are high that the decryptor can be used as a Bleichenbacher oracle. Don't forget to take into account the actual XML data, i.e., the assertion encrypted with the new session key; by submitting valid or invalid XML, or by removing signatures from the SAML message or the assertion you may increase your chances of detecting differences in the returned responses.
Probing for Oracles in CBC-Mode Decryption
Another known attack on XML Encryption is aimed at the Cipher Block Chaining (CBC) mode, which can be used with the block ciphers AES or 3DES [2]. The attack is described in detail in this referenced paper [3] and is quite similar to Padding-Oracle attacks on CBC mode; the malleability of CBC mode encryption enables the attacker to perform a bytewise, adaptive manipulation of the ciphertext blocks which are subsequently sent to the decryptor. In most cases, the manipulated ciphertext will not decrypt to valid XML and an error will be returned. Sometimes, however, the plaintext will be parsed as valid XML, in which cases an error is thrown later on at the application layer. The attacker observes the differences in the responses in order to turn the decryptor into a ciphertext validity oracle which can be used to break the encryption. Due to some particularities of the XML format, this attack can be very efficient, enabling decryption with about 14 requests per byte, and it is even possible to fully automate the process [7].
In order to determine if a particular SAML service provider is vulnerable to this attack, we can avoid the cumbersome ciphertext manipulation, if we are in possession of the decryptor's public key: In the Encryption Attacker tab of EsPReSSO, add the public key certificate to the Certificate field (if necessary) and insert a symmetric key of your own devising into the Symmetric Key text field. Select an appropriate RSA encryption method and click the Encrypt button to apply the new EncryptedKey element to the original SAML message.
An XML message can now be inserted into the XML data text field. Select a CBC mode encryption algorithm and click Encrypt to apply the changes. As in the example above, press Burp's Go or Forward button to send the message and carefully inspect the response. Try sending invalid XML, e.g., by not closing a tag or using the `&` character without a valid entity and keep an eye open for differences in the returned responses. To manipulate the padding, the text field on the right side shows the hexadecimal representation of the plaintext, including the CBC padding. If you send a single block and set the last byte, which indicates the padding length to the blocksize, i.e. 16 or 0x10 for AES, the ciphertext should decrypt into an empty string and is generally considered "valid" XML.
Please refer to the original paper for more details, tips, and tricks for performing the actual attack [3].
Summary
The new XML Encryption attacker included in EsPReSSO can help security auditors to quickly assess if a SAML endpoint is vulnerable to known attacks against XML Encryption. To this end, the decryptor's public key is used in order to send suitable test vectors that can be provided in plaintext. Ciphertext manipulation is, therefore, not required. The actual process of decrypting an intercepted SAML message is, however, considered out of scope and not implemented in EsPReSSO.
In case you wonder how XML Encryption can be used in a secure fashion, here are some considerations [6]:
Always use an authenticated encryption mode such as AES-GCM instead of the CBC-mode encryption.
Using RSA-PKCS1 v1.5 within XML Encryption is particularly difficult to do in a secure manner, and it is recommended to use RSA with Optimal Asymmetric Encryption Padding (OAEP) instead [2].
Apply a digital signature over the whole SAML response, and ensure it is properly validated before attempting to decrypt the assertion. This should thwart the attack as a manipulated response can be recognized as such and should be rejected.
This morning I've found an scaring surprise on my Firefox Quantum. Casually it was connected to a proxy when an unexpected connection came up, the browser was connecting to an unknown remote site via HTTP and downloading a ZIP that contains an ELF shared library, without any type of signature on it.
This means two things
1) the owner of that site might spread malware infecting many many people. 2) the ISP also might do that.
Ubuntu Version:
Firefox Quantum version:
The URL: hxxp://ciscobinary.openh264.org/openh264-linux64-0410d336bb748149a4f560eb6108090f078254b1.zip
The zip contains these two files: 3f201a8984d6d765bc81966842294611 libgmpopenh264.so 44aef3cd6b755fa5f6968725b67fd3b8 gmpopenh264.info
The info file: Name: gmpopenh264 Description: GMP Plugin for OpenH264. Version: 1.6.0 APIs: encode-video[h264], decode-video[h264]
So there is a remote codec loading system that is unsigned and unencrypted, I think is good to be aware of it.
In this case the shared library is a video decoder, but it would be a vector to distribute malware o spyware massively, or an attack vector for a MITM attacker.
