This Week In Security: Fragattacks, The Pipeline, Codecov, And IPv6

May 14, 2021 by Jonathan Bennett 26 Comments

Some weeks are slow, and the picking are slim when discussing the latest security news. This was not one of those weeks.

First up is Fragattacks, a set of flaws in wireless security protocols, allowing unauthenticated devices to inject packets into the network, and in some cases, read data back out. The flaws revolve around 802.11’s support for packet aggregation and frame fragmentation. The whitepaper is out, so let’s take a look.

Fragmentation and aggregation are techniques for optimizing wireless connections. Packet aggregation is the inclusion of multiple IP packets in a single wireless frame. When a device is sending many small packets, it’s more efficient to send them all at once, in a single wireless frame. On the other hand, if the wireless signal-to-noise ratio is less than ideal, shorter frames are more likely to arrive intact. To better operate in such an environment, long frames can be split into fragments, and recombined upon receipt.

There are a trio of vulnerabilities that are built-in to the wireless protocols themselves. First up is CVE-2020-24588, the aggregation attack. To put this simply, the aggregation section of a wireless frame header is unauthenticated and unencrypted. How to exploit this weakness isn’t immediately obvious, but the authors have done something clever.

First, for the purposes of explanation, we will assume that there is already a TCP connection established between the victim and an attacker controlled server. This could be as simple as an advertisement being displayed on a visited web page, or an image linked to in an email. We will also assume that the attacker is performing a Man in the Middle attack on the target’s wireless connection. Without the password, this only allows the attacker to pass the wireless frames back and forth unmodified, except for the aggregation header data, as mentioned. The actual attack is to send a special IP packet in the established TCP connection, and then modify the header data on the wireless frame that contains that packet.

When the victim tries to unpack what it believes to be an aggregated frame, the TCP payload is interpreted as a discrete packet, which can be addressed to any IP and port the attacker chooses. To put it more simply, it’s a packet within a packet, and the frame aggregation header is abused to pop the internal packet out onto the protected network. Continue reading “This Week In Security: Fragattacks, The Pipeline, Codecov, And IPv6” →

This Week In Security: Dan Kaminsky, Banned From Kernel Development, Ransomware, And The Pentagon’s IPv4 Addresses

April 30, 2021 by Jonathan Bennett 22 Comments

This week we’re starting off with a somber note, as Dan Kaminsky passed at only 42, of diabetic ketoacidosis. Dan made a name for himself by noticing a weakness in DNS response verification that could allow attackers to poison a target DNS resolver’s cache. A theoretical attack was known, where spoofed DNS responses could collide with requests, but Time-To-Live values meant that DNS requests only go out once per eight hours or so. The breakthrough was realizing that the TTL limitation could be bypassed by requesting bogus subdomains, and aiming the spoofed responses at those requests. This simple technique transformed a theoretical attack that would take 87 years to a very real 10 second attack. Check out the period video after the break, where Dan talked about his efforts in getting the problem fixed.
Continue reading “This Week In Security: Dan Kaminsky, Banned From Kernel Development, Ransomware, And The Pentagon’s IPv4 Addresses” →

This Week In Security: Sudo, Database Breaches, And Ransomware

January 29, 2021 by Jonathan Bennett 27 Comments

We couldn't resist, OK? — Obligatory XKCD

Sudo is super important Linux utility, as well as the source of endless jokes. What’s not a joke is CVE-2021-3156, a serious vulnerability around incorrect handling of escape characters. This bug was discovered by researchers at Qualys, and has been in the sudo codebase since 2011. If you haven’t updated your Linux machine in a couple days, you may very well be running the vulnerable sudo binary still. There’s a simple one-liner to test for the vulnerability:

sudoedit -s '\' `perl -e 'print "A" x 65536'`

In response to this command, my machine throws this error, meaning it’s vulnerable:

malloc(): corrupted top size Aborted (core dumped)

To understand the problem with sudo, we have to understand escape characters. It really boils down to spaces in file and folder names, and how to deal with them. You want to name your folder “My Stuff”? That’s fine, but how do you interact with that directory name on the command line, when spaces are the default delimiter between arguments? One option is to wrap it in quotation marks, but that gets old in a hurry. The Unix solution is to use the backslash character as an escape character. Hence you can refer to your fancy folder as My\ Stuff. The shell sees the escape character, and knows to interpret the space as part of the folder name, rather than an argument separator. Escape characters are a common vulnerability location, as there are plenty of edge cases. Continue reading “This Week In Security: Sudo, Database Breaches, And Ransomware” →

Hackaday Links: October 4, 2020

October 4, 2020 by Dan Maloney 9 Comments

In case you hadn’t noticed, it was a bad week for system admins. Pennsylvania-based United Health Services, a company that owns and operates hospitals across the US and UK, was hit by a ransomware attack early in the week. The attack, which appears to be the Ryuk ransomware, shut down systems used by hospitals and health care providers to schedule patient visits, report lab results, and do the important job of charting. It’s not clear how much the ransomers want, but given that UHS is a Fortune 500 company, it’s likely a tidy sum.

And as if an entire hospital corporation’s IT infrastructure being taken down isn’t bad enough, how about the multi-state 911 outage that occurred around the same time? Most news reports seemed to blame the outage on an Office 365 outage happening at the same time, but Krebs on Security dug a little deeper and traced the issue back to two companies that provide 911 call routing services. Each of the companies is blaming the other, so nobody is talking about the root cause of the issue. There’s no indication that it was malware or ransomware, though, and the outage was mercifully brief. But it just goes to show how vulnerable our systems have become.

Our final “really bad day at work” story comes from Japan, where a single piece of failed hardware shut down a $6-trillion stock market. The Tokyo Stock Exchange, third-largest bourse in the world, had to be completely shut down early in the trading day Thursday when a shared disk array failed. The device was supposed to automatically failover to a backup unit, but apparently the handoff process failed. This led to cascading failures and blank terminals on the desks of thousands of traders. Exchange officials made the call to shut everything down for the day and bring everything back up carefully. We imagine there are some systems people sweating it out this weekend to figure out what went wrong and how to keep it from happening again.

With our systems apparently becoming increasingly brittle, it might be a good time to take a look at what goes into space-rated operating systems. Ars Technica has a fascinating overview of the real-time OSes used for space probes, where failure is not an option and a few milliseconds error can destroy billions of dollars of hardware. The article focuses on the RTOS VxWorks and goes into detail on the mysterious rebooting error that affected the Mars Pathfinder mission in 1997. Space travel isn’t the same as running a hospital or stock exchange, of course, but there are probably lessons to be learned here.

As if 2020 hasn’t dealt enough previews of various apocalyptic scenarios, here’s what surely must be a sign that the end is nigh: AI-generated PowerPoint slides. For anyone who has ever had to sit through an endless slide deck and wondered who the hell came up with such drivel, the answer may soon be: no one. DeckRobot, a startup company, is building an AI-powered extension to Microsoft Office to automate the production of “company compliant and visually appealing” slide decks. The extension will apparently be trained using “thousands and thousands of real PowerPoint slides”. So, great — AI no longer has to have the keys to the nukes to do us in. It’ll just bore us all to death.

And finally, if you need a bit of a palate-cleanser after all that, please do check out robotic curling. Yes, the sport that everyone loves to make fun of is actually way more complicated than it seems, and getting a robot to launch the stones on the icy playing field is a really complex and interesting problem. The robot — dubbed “Curly”, of course — looks like a souped-up Roomba. After sizing up the playing field with a camera on an extendable boom, it pushes the stone while giving it a gentle spin to ease it into exactly the right spot. Sadly, the wickedly energetic work of the sweepers and their trajectory-altering brooms has not yet been automated, but it’s still pretty cool to watch. But fair warning: you might soon find yourself with a curling habit to support.

Busting GPS Exercise Data Out Of Its Garmin-controlled IoT Prison

July 28, 2020 by Mike Szczys 21 Comments

If you take to the outdoors for your exercise, rather than walking the Sisyphusian stair machine, it’s nice to grab some GPS-packed electronics to quantify your workout. [Bunnie Huang] enjoys paddling the outrigger canoe through the Singapore Strait and recently figured out how to unpack and visualize GPS data from his own Garmin watch.

By now you’ve likely heard that Garmin’s systems were down due to a ransomware attack last Thursday, July 23rd. On the one hand, it’s a minor inconvenience to not be able to see your workout visualized because of the system outage. On the other hand, the services have a lot of your personal data: dates, locations, and biometrics like heart rate. [Bunnie] looked around to see if he could unpack the data stored on his Garmin watch without pledging his privacy to computers in the sky.

Obviously this isn’t [Bunnie’s] first rodeo, but in the end you don’t need to be a 1337 haxor to pull this one off. An Open Source program called GPSBabel lets you convert proprietary data formats from a hundred or so different GPS receivers into .GPX files that are then easy to work with. From there he whipped up less than 200 lines of Python to plot the GPS data on a map and display it as a webpage. The key libraries at work here are Folium which provides the pretty browsable map data, and Matplotlib to plot the data.

These IoT devices are by all accounts amazing, listening for satellite pings to show us how far and how fast we’ve gone on web-based interfaces that are sharable, searchable, and any number of other good things ending in “able”. But the flip side is that you may not be the only person seeing the data. Two years ago Strava exposed military locations because of an opt-out policy for public data sharing of exercise trackers. Now Garmin says they don’t have any indications that data was stolen in the ransomware attack, but it’s not a stretch to think there was a potential there for such a data breach. It’s nice to see there are Open Source options for those who want access to exercise analytics and visualizations without being required to first hand over the data.

This Week In Security: F5, Novel Ransomware, Freta, And Database Woes

July 10, 2020 by Jonathan Bennett 5 Comments

The big story of the last week is a problem in F5’s BIG-IP devices. A rather trivial path traversal vulnerability allows an unauthenticated user to call endpoints that are intended to be restricted to authenticated. That attack can apparently be as simple as:

'https://[F5 Host]/tmui/login.jsp/..;/tmui/locallb/workspace/tmshCmd.jsp?command=list+auth+user+admin'

A full exploit has been added to the metasploit framework. The timeline on this bug is frighteningly quick, as it’s apparently being actively exploited in the wild. F5 devices are used all over the world, and this vulnerability requires no special configuration, just access to the opened management port. Thankfully F5 devices don’t expose the vulnerable interface to the internet by default, but there are still plenty of ways this can be a problem.

Freta

Microsoft has made a new tool publicly available, Freta. This tool searches for rootkits in uploaded memory snapshots from a Linux VM. The name, appropriately, is taken from the street where Marie Curie was born.

The project’s namesake, Warsaw’s Freta Street, was the birthplace of Marie Curie, a pioneer of battlefield imaging.

The impetus behind the project is the realization that once a malicious actor has compromised a machine, it’s possible to compromise any security software running on that machine. If, instead, one could perform a security x-ray of sorts, then a more reliable conclusion could be reached. Freta takes advantage of the VM model, and the snapshot capability built into modern hypervisors.

Continue reading “This Week In Security: F5, Novel Ransomware, Freta, And Database Woes” →

This Week In Security: HaveIBeenPwned And Facebook Attack Their Customers

June 19, 2020 by Jonathan Bennett 27 Comments

We’re fans of haveibeenpwned.com around here, but a weird story came across my proverbial desk this week — [Troy Hunt] wrote a malicious SQL injection into one of their emails! That attack string was a simple ';--

Wait, doesn’t that look familiar? You remember the header on the haveibeenpwned web page? Yeah, it’s ';--have i been pwned?. It’s a clever in-joke about SQL injection that’s part of the company’s brand. An automated announcement was sent out to a company that happened to use the GLPI service desk software. That company, which shall not be named for reasons that are about to become obvious, was running a slightly out-of-date install of GLPI. That email generated an automated support ticket, which started out with the magic collection of symbols. When a tech self-assigned the ticket, the SQL injection bug was triggered, and their entire ticket database was wiped out. The story ends happily, thanks to a good backup, and the company learned a valuable lesson. Continue reading “This Week In Security: HaveIBeenPwned And Facebook Attack Their Customers” →