Posts tagged: Stories

Dec 25 2013

4096-bit RSA Key Extraction Attack via Acoustic Cryptanalysis

A trio of scientists have verified that results they first presented nearly 10 years ago are in fact valid, proving that they can extract a 4096-bit RSA key from a laptop using an acoustic side-channel attack that enables them to record the noise coming from the laptop during decryption, using a smartphone placed nearby. The attack, laid out in a new paper, can be used to reveal a large RSA key in less than an hour.

Acoustic Cryptanalysis
Parabolic microphone extracting an RSA key from a target laptop

The attack relies on a number of factors, including proximity to the machine performing the decryption operation and being able to develop chosen ciphertexts that incite certain observable numerical cancellations in the GnuPG algorithm. Over several thousand repetitions of the algorithm’s operation, the researchers discovered that there was sound leakage they could record over the course of fractions of a second and interpret, resulting in the discovery of the RSA key in use.

Their attack works against a number of laptop models and they said that there are a number of ways that they could implement it, including through a malicious smartphone app running on a device near a target machine. They could also implement it through software on a compromised mobile device of through the kind of eavesdropping bugs used by intelligence agencies and private investigators.

The developers of GnuPG have developed a patch for the vulnerability that the Israeli researchers used, implementing a technique known as blinding. The patch is included in version 1.4.16 of GnuPG. Shamir and his co-authors, Daniel Genkin and Eran Tromer, said that they also could perform their attack from a greater distance using a parabolic microphone and may also work with a laser microphone or vibrometer.

Research Paper: RSA Key Extraction via Low-Bandwidth Acoustic Cryptanalysis

Dec 15 2013

EBay Remote Code Execution Vulnerability Demonstrated

EBay Exploit
A German Security researcher has demonstrated a critical vulnerability on Ebay website.

He found a controller which was prone to remote-code-execution due to a type-cast issue in combination with complex curly syntax.

In a demo video, he exploited this RCE flaw on EBay website, and managed to display output of phpinfo() PHP function on the web page, just by modifying the URL and injecting code in that.

According to an explanation on his blog, he noticed a legitimate URL on EBay:

https://sea.ebay.com/search/?q=david&catidd=1

and modified the URL to pass any array values including a payload:

https://sea.ebay.com/search/?q[0]=david&q[1]=sec{${phpinfo()}}&catidd=1

Video Demonstration:

David has already reported the flaw responsibly to the Ebay Security Team and they have patched it early this week.

Source: eBay : Remote Code Execution

Sep 27 2013

16-Year Old Arrested Over World’s Biggest Cyber Attack

Spamhaus DDoS AttackIn March 2013, a distributed denial of service (DDoS) attack of unprecedented ferocity was launched against the servers of Spamhaus, an international non-profit dedicated to battling spam.

The March Spamhaus attack peaked at 300 gigabits per second, Spamhaus CEO Steve Linford told the BBC at the time – the largest ever recorded, with enough force to cause worldwide disruption of the internet.

In April, one suspect was arrested in Spain.

Now, it’s come to light, another suspect was also secretly arrested in April – this one being a London schoolboy.

The 16-year-old was arrested as part of an international dragnet against a suspected organised crime gang, reports the London Evening Standard.

Detectives from the National Cyber Crime Unit detained the unnamed teenager at his home in southwest London.

The newspaper quotes a briefing document on the British investigation, codenamed Operation Rashlike, about the arrest:

“The suspect was found with his computer systems open and logged on to various virtual systems and forums. The subject has a significant amount of money flowing through his bank account. Financial investigators are in the process of restraining monies”.

Officers seized his computers and mobile devices.

The boy’s arrest, by detectives from the National Cyber Crime Unit, followed an international police operation against those suspected of carrying out the massive cyber attack, which slowed down the internet worldwide.

The briefing document says that the DDoS affected services that included the London Internet Exchange.

The boy has been released on bail until later this year, the London Evening Standard reports.

Sep 16 2013

Android WebView Exploit Allows Hackers to Install Malicious Apps

There’s a vulnerability that affects WebView control in Android applications installed on Android devices running versions older than 4.2.

This vulnerability makes a large number of Android applications act as a hacker pipeline into user’s devices and provides a way to install malicious software, send SMSs and more.

Android WebView Exploit

WebView allows the user to view a web application (or just a web page) as a part of an ordinary Android application. The WebView class is an extension of Android’s View class that allows you to display web pages as a part of the appication’s screen layout.

All that WebView does, by default, is show a web page. When developing an Android application, if the web page you plan to load in your WebView uses JavaScript, you must enable JavaScript for your WebView.

Once JavaScript is enabled, you can create interfaces between your application code and your JavaScript code.

addJavascriptInterface (Object object, String name) method:
The addJavascriptInterface method injects a supplied Java object into WebView.
The object is injected into the JavaScript context of the main frame, using a supplied name and this allows the Java object’s methods to be accessed from JavaScript.

For applications running Android 4.1 or older, all public methods (including the inherited ones) can be accessed, so when a user’s installed application with addJavascriptInterface method loads an external webpage it can use WebView and javascript to call a java object (like a ‘Javascript pipeline’ and usage of reflection to invoke any other unregistered Java class) which allows attackers to call Android’s Java methods.

The Fix:
For applications running Android 4.2 all public methods that are annotated with JavascriptInterface can be accessed from JavaScript.

So if you develop an application for SDK version 17 or higher, you must add the @JavascriptInterface annotation to any method that you want available to your JavaScript.

If you do not provide the annotation, the method is not accessible by your web page when running on Android 4.2 or higher.

Infection Method:
Users can be infected when they click on a URL link using a vulnerable application that allows opening a Java enabled browser or web page.

The device will automatically perform the malicious actions that were ordered in the malicious web page that contain those JavaScript commands.

The commands in the JavaScript code can enable attackers to install malicious software, send SMSs, steal personal information and more.

Source: Analyzing an Android WebView exploit : AVG Official Blogs

Sep 02 2013

Facebook Vulnerability that Allowed any Photo to be Deleted Earns $12,500 Bounty

Facebook BountyAn Indian electronics and communications engineer who describes himself as a “security enthusiast with a passion for ethical hacking” has discovered a Facebook vulnerability that could have allowed for any photo on the site to be deleted without the owner’s knowledge.

Arul Kumar, a 21 year old from Tamil Nadu, discovered that he could delete any Facebook image within a minute, even from verified pages, all without any interaction from the user.

For his efforts in reporting the vulnerability to Facebook’s whitehat bug bounty program Kumar received a reward of $12,500.

The vulnerability that he discovered was based around exploiting the mobile version of the social network’s Support Dashboard, a portal that allows users to track the progress of any reports they make to the site, including highlighting photos that they believe should be removed.

Kumar explained his bug by using a demo account, as well as sending Facebook a proof of concept video in which he showed how he could have removed Mark Zuckerberg’s own photos from his album.

By following Facebook’s whitehat guidelines he was able to pick up his deserved bounty.