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Ubuntu Security Podcast

Episode 165

34 min • 24 juni 2022

Overview

This week Camila dives into the details on some of the most prolific buzzwords flying around the cybersecurity community, plus we cover security updates for BlueZ, the Linux kernel, Intel Microcode, QEMU, Apache and more.

This week in Ubuntu Security Updates

58 unique CVEs addressed

[USN-5481-1] BlueZ vulnerabilities [00:38]

  • Affecting Bionic (18.04 LTS), Focal (20.04 LTS)
  • Not all vulnerabilities / security issues get CVEs ;)
  • Possible OOB read in A/V Remote Control Protocol profile
  • Possible OOB write and a possible 1-byte buffer overflow in A/V Distribution Transport Protocol profile

[LSN-0087-1] Linux kernel vulnerability [01:20]

  • 2 CVEs addressed in Trusty ESM (14.04 ESM), Xenial ESM (16.04 ESM), Bionic (18.04 LTS), Focal (20.04 LTS), Jammy (22.04 LTS)
  • 2 different netfilter issues
    • OOB write (can be mitigated by disabling unprivileged user namespaces)
    • UAF
Kernel type 22.04 20.04 18.04 16.04 14.04
aws 87.1 87.2 87.1
aws-5.4 87.1
aws-hwe 87.2
azure 87.1 87.1
azure-4.15 87.1
azure-5.4 87.1
gcp 87.1 87.1 87.1
gcp-4.15 87.1
gcp-5.4 87.1
generic-4.15 87.1 87.1
generic-4.4 87.1 87.1
generic-5.4 87.1 87.1
gke 87.1 87.1
gke-4.15 87.1
gke-5.4 87.1
gkeop 87.1
gkeop-5.4 87.1
ibm 87.1 87.1
linux 87.1
lowlatency 87.1
lowlatency-4.15 87.1 87.1
lowlatency-4.4 87.1 87.1
lowlatency-5.4 87.1 87.1
oem 87.1
canonical-livepatch status

[USN-5485-1] Linux kernel vulnerabilities [02:14]

  • 3 CVEs addressed in Trusty ESM (14.04 ESM), Xenial ESM (16.04 ESM), Bionic (18.04 LTS), Focal (20.04 LTS), Impish (21.10), Jammy (22.04 LTS)
  • All GA and some HWE kernels
  • Intel MMIO stale data
    • Mentioned in passing in last week’s episode - kernels are now available as well as microcode to mitigate these issues - once have installed the new kernel can see if vulnerable via a new sysfs file:
cat /sys/devices/system/cpu/vulnerabilities/mmio_stale_data
  • Will display either Not affected, Vulnerable (no mitigation), Vulnerable: Clear CPU buffers attempted, no microcode or Mitigation: Clear CPU buffers if have mitigation enabled and microcode to support it
  • Will also display info on SMT since if vulnerable then need to disable SMT to be completely protected
  • Mitigation comes with a performance hit so if not doing untrusted virtualisation can perhaps disable it (but please do your own research as needed 😉) via kernel command-line option:
mmio_stale_data=full # or 'full,nosmt'  or 'off'

[USN-5484-1] Linux kernel vulnerabilities [05:22]

[USN-5486-1] Intel Microcode vulnerabilities [06:01]

[USN-5483-1] Exempi vulnerabilities [07:08]

[USN-5482-1] SPIP vulnerabilities [07:55]

[USN-5487-1] Apache HTTP Server vulnerabilities [08:28]

[USN-5488-1] OpenSSL vulnerability [08:53]

  • 1 CVEs addressed in Bionic (18.04 LTS), Focal (20.04 LTS), Impish (21.10), Jammy (22.04 LTS)
  • c_rehash - very similar to CVE-2022-1292 (Episode 159) - possible code execution if running it against certificates with crafted file names - unlikely anyone is doing this in practice, plus upstream say this is deprecated and instead should just use openssl rehash instead

[USN-5489-1] QEMU vulnerabilities [09:57]

Decoding cybersecurity buzzwords (part 1) [10:45]

  • From ransomware to botnets and phishing, Camila dives into the details on some of the most prolific buzzwords flying around the cybersecurity community

Transcript

Hello listener! Welcome to another segment o’mine in the Ubuntu Security Podcast! It’s been a while, but I have returned to bring some real buzz into today’s episode! How, you might ask? The buzz will come from the buzzwords we will be exploring…cyber security buzzwords to be more specific. Let’s start by defining what a buzzword is, for those who might not know this term: a buzzword is a word - or a term - that, as the name suggests, is currently buzzing. It’s a word that is popular within the scope of its usage. Everyone says it all the time, and it seems like you can’t escape it. The most popular articles about topics in a specific field use it every other sentence, people put them in big, bold and shiny letters right there on the title of their scientific papers, and even your baby’s first words end up being that buzzword because they end up hearing it more than the eternal and classic infant buzz phrase “Say mama!”. A buzzword is, therefore, a fashionable word at a specific point in time. Every field has its own, and cyber security is not exempt from them. Today, I want to actually explore some of the cyber security buzzwords we have and actually try to demystify them, as buzzwords can become something much more absurd or grandiose than they actually are just because everyone is choosing to use them. I think we all remember the era of the super low-rise jeans and can agree (or maybe agree to disagree) that just because something is being used by everyone out there, it does not mean it deserves all the hype…of course that is my own opinion on the subject matter that is low-rise jeans. As for the buzzwords, the statement stands! So, let’s bring up some of these super duper amazingly popular buzzwords in to play here, let’s actually define what they are for the ones out there that might not be cyber-security wizards, and let’s remove the buzzing that these buzzwords might have brought into our minds, shall we?

Buzzword #1: ransomware. Aaah, ransomware. You see this simple and yet deadly word everywhere. “Defend yourself against ransomware!”, “Ransomware might be just around the corner!”, “No need to fear ransomware anymore!”. It was the dawn of 2017 when ransomware became a thing to people outside of the cyber security community because of the infamous WannaCry malware. That picture with a red pop-up window telling you that all of your files had been encrypted and could only be recovered after some type of crypto currency payment was made to the attackers was absolutely everywhere! And after that, the ransomware wave only got stronger, with new and improved types showing up all the time, an honorable mention being the Petya variants. Anyway, since WannaCry was such a big deal at the time, and people were so scared of it after it left behind its trail of mayhem and huge amounts of lost data, ransomware became THE word chosen by various cybersecurity companies to describe that which is your main enemy in the digital world, the supervillain in this installment of the cyber security movie series that is actually our real lives. All defense tools now implement some type of measure against ransomware, because if they don’t, you know that clients of said tool will ask “but what about defending against ransomware?”, because that, my friends, is the buzzword that comes to their minds. Like the word “computer virus” in the early 2000s. Computer viruses still exist, but you don’t see people freaking out about it anymore, because now we have the “antivirus”. Phew, problem solved, right? So no need to have this as a buzzword anymore. However, just like computer viruses existed before the 2000s and still exist to this day, ransomware also existed before WannaCry and much worse versions of it will continue to exist while there still are vulnerabilities and hackers out there, which is to say…probably forever. The only difference is, we now live in a time where people seem to care about it a little bit more, maybe because they are not implementing security measures to be safe against it, or at least they are not doing it very well. But I am getting ahead of myself here. Let’s first talk about what ransomware really is, which is actually something very simple to do: a ransomware is a malware, as a computer virus is also a malware. A malware is a ‘malicious software’, or, in other words, a software that executes in a computing device and that does things that the owner of the device might not want it to do, like…for example, encrypt all of your files and not allow you to access them. That is what ransomware does, in most cases. The main idea is, a ransomware will be a malicious software that will prevent you from accessing your files until you pay some amount of money to the malicious entity that was able to get that ransomware to run in your network devices in the first place…so, until you pay a ransom to the kidnapper of your data. Of course this only works if you have someone on the other side waiting to exchange the money for the key that will decrypt your files, or else, you could simply have a very destructive trojan, or worm, or whatever other malware that is combined with the file encrypting functionality in order for the malicious software itself to spread through the network before actually causing the data harm it does. The question now is, whatever is the ransomware-hybrid malware that targeted you and your network, the only way to recover the data you lost, the data as it was during the time of total encryption, is to pay the ransom. Should you? Cyber security professionals usually recommend against paying ransom, as it only shows hackers that they can continue launching ransomware attacks to get what they want. The correct way to avoid your files from being forever lost after your network has been infected by one of these nasty malwares is to recover data from the backup server you set up…you did set up a backup server to store the backup for all of your company data, right? I know, I know…not always it will be the case that people will be able to set backups, and then, recovering all that is lost might be a much more difficult task if you decide to not pay the ransom. But come on…we live at a time where cyber security should no longer be put in the benches, and you should be highly concerned about possible attacks, especially attacks related to the ever popular buzzword ransomware. Save some of your budget for backups, you won’t regret it.

Buzzword #2: botnets. ‘Botnet’ is an interesting buzzword because it opens the door to many other tech buzzwords that are in everyone’s minds out there right now…like crypto mining, for example. Why? Because you can use botnets to perform crypto mining…you can also use botnets to spread malware, including ransomware. Oh…and botnets…their participants usually include lots of IoT devices! BAM, another buzzword right there! Now would you look at that! Seems like instead of a buzzword, we actually have a buzzword magnet in our hands ladies and gentlemen. So…yes, maybe ‘botnet’ is not the hottest buzzword out there right now, but I decided to include it in the list because I feel like it is a disguised buzzword. What do I mean by disguised? It’s the word that is in the subtitle for an article named “CRYPTO MINING HACKER GANG CAUSES DAMAGES TO COMPANY X”, or the word that is implied in a video that is named “IoT DEVICE Y SECURITY VULNERABILITY ONCE AGAIN EXPOSED BY MASSIVE DENIAL OF SERVICE ATTACK”, or even the word that is a part of a title or a conversation about cyber security, cyber attacks and vulnerabilities, but it might not be the one in big bold flashy fonts, like it was the case for our dearest friend ransomware. But it all comes back to the botnets eventually. So what is a botnet? As the name suggests, it is a network of bots! Wooow, could I get a round of applause for that definition, please and thank you very much! When we think about a robot, we think about a technological humanoid that speaks in a digitalized voice and obeys commands without question, unless they are actually trying to take over the planet and overthrow human supremacy…but that is a topic for another podcast to maybe discuss. The point here is: what is a computer if not a robot? No, it does not possess humanoid form most of the time, but it does communicate with us through a digital screen and it will execute commands that the software it is running tells it to, this software being created and programmed by a human being. So…yes…robots are computers, computers are robots, or at least…fancy humanoid robots and even cute round cleaning robots need computers to exist and computers are the basis to create a robot. So when we say botnet, we are actually referring to a network of computers. A network of computers, or a group of computers, which are all performing some type of common activity, executing software with the same purpose… and unfortunately for us, in this case it is a malicious purpose. Botnets are created through the infection of computing devices. A hacker releases malware on the Internet and this malware is able to propagate, infecting various devices connected to our fairest of ladies, usually devices that are vulnerable to some type of specific vulnerability. So, yes, once again we have malwares being a problem and ruining our days…surprise, surprise. Once infected, the device becomes a robot, a “mindless” soldier in an army of many that will respond to a hacker, most likely the one that created the malware. It connects back to this hacker, usually sending some type of short and sweet - bitter sweet for us, that is - message to a command and control server, which we can see as an HQ, but is actually nothing more than an attacker controlled device. And then…it waits. It continuously calls home to indicate that it is a part of the malicious group of infected devices that are “at the hacker’s service”, and it expects to eventually receive a message that will contain instructions which will give it an attack target and an attack to launch on that target. The malware that is running on the infected device, our bot, will contain the code or will receive and process the code that will allow this attack to be carried out, and then we have a huge amount of possibilities that we can consider for this attack, one of them being: the bots could be instructed to send absurd amounts of data through the network to a specific target. The target device gets overwhelmed and the service it provides through the network can no longer be accessed by legitimate users because the device crashes. This is a denial of service attack, which is very hard to stop at the source, as you have thousands of sources, most of which the device owners don’t even have malicious intent. The devices got hacked and are secretly and mercilessly being used to the advantage of the attacker. Granted…the reason for the infection, the presence of the vulnerability that initially caused this could be the owner’s fault. Maybe they wouldn’t have been unwillingly attacking the server of their favorite website had they applied that patch that recently came out for a critical vulnerability, however, you can’t really call them the mastermind of it all when all they did was keep a vulnerable computer, can you? Anyway, I might leave that philosophical question for a later time…for now, another well known use for botnets is crypto mining. Infect, divide and profit! Why use your own computer and your own resources to mine crypto currency when you have hundreds of thousands of unpatched IoT devices at your disposal to mine for you? That’s what the hackers think…not me….just to be veeeery clear. A botnet can also be used to spread ransomware. The bots worry about creating other bots as well as infecting devices in their own local networks that might make a hacker profit from a ransomware attack. And it all ties in beautifully to create the most amazing of buzzword sentences: Phishing campaign allows for creation of ransomware botnet! Oh…wait…there is a buzzword in there we have yet to talk about…

Buzzword #3: phishing! Did you like how I introduced this one by just name-dropping it previously? Since I gave it such a direct introduction, let’s also give it a direct definition. Phishing is a type of social engineering attack where an attacker throws what we can only call as the equivalent to “bait” into the Internet “ocean” in hopes of hooking some “fish”, in their fishing rods. So…the “fish” are like the victims of the attack, if that wasn’t clear enough for you… Our situation therefore, is kind of like real fishing, but in a different context, because here we are looking at people getting fooled into clicking on links that will cause them to access malicious websites, and then share sensitive information like passwords and credit card numbers through that website, all because they get fooled into doing it by a very clever attacker which is using of their social engineering skills achieve this. They could also simply get fooled into responding directly to a well crafted message with sensitive information they wouldn’t even share with their own diaries! Or maybe just with their diaries, but not other people. The question which remains is: what is social engineering? To put it simply, a social engineer is someone that knows how to “hack” the human psyche. To put it not so simply, it is the art - can I call it that? - of manipulating other people into doing something they might not want to have done in the first place. So, every spy movie when you see the almighty main character get into a building they shouldn’t by fooling the guard and making them believe they actually work there because they are wearing a fancy suit and spilling out complex terms to a phone…well that is social engineering. The super spy plays the part and gives no time for the guard to think too much about whether they are actually a legitimate authorized person or not, because when the guard starts questioning it, they emphatically say something in the lines of “Oh my god…I am going to be late to my meeting and you do not want Mr. Whatever to hear about this’. Mr. Whatever is an actual big boss around the place and Mr. Guard worries he will get fired if he doesn’t comply immediately, so just this time, he skips the ID checking phase of the process to let super spy waltz into the building unscathed. His fear of getting fired was used against him in order to make him do something he wouldn’t do were he thinking clearly, not affected by emotion: skip a part of the identification process of a person wanting to access the building. When we talk about spy movies of course we have a much more interesting example than when we are talking about actual phishing campaigns, but the underlying idea is the same in both. The difference is, in phishing attacks, a hacker will usually send an e-mail or a text message to a bunch of random people with a message that will toy with their emotions somehow. They focus on quantity instead of quality because eventually someone is bound to be freaked out by the email they get saying that their bank account will be closed if they don’t immediately click the link in the message and change their password using the form provided. They click the link without paying attention to the website URL, which is not at all related to the one of their bank’s actual website, and are redirected to a webpage which looks exactly like the password changing page you would get had you accessed this legitimate bank website. They input their data, which is quickly sent to the attacker, because they are the actual entity controlling the device behind said website, and now, this attacker has the password to this person’s bank account. Fishing rod: fake email sent to thousands of people saying the bank will close accounts that don’t change their passwords. Bait: the human feeling of desperation one might get when thinking about having their bank account suddenly be inaccessible, caused by the wording and official looking appearance of the email message that was sent. Fish who bite on that bait: people who believe this message and don’t pay too much attention to the signs that indicate that it is fake. Most times, people who are not that tech savvy and don’t even know how it is possible that a fake website could have the same appearance as the one from the actual bank. If it looks like the bank webpage, it can only be the bank webpage…right? So…yes, I am unfortunately talking about all of the grandmas out there, which end up being a very common victim of these types of attacks. But do not get me wrong. I am not saying here that if you are not a grandma that you are unaffected by phishing attacks. Social engineering techniques go way beyond fear or desperation, and anyone can be a target should a hacker strike the correct emotions on this target. Remember a certain Nigerian prince who was asking for a small sum of money only to return 10 times this amount to you as soon as their investment worked? Greed can also be your downfall. So the main tip for those that are worried about falling for phishing scams is simple: if something looks like it is too good to be true, it probably is. Also…if something seems too crazy to be true, maybe ask trustworthy people related to the craziness in question if that message you are receiving is indeed legitimate. So…for our bank situation, call your bank manager! Have more than one information source and breathe before making any harsh decisions and clicking the link that will ask you for your credentials or for any kind of sensitive information for absolutely no reason! I mean…why do you need my credit card number if I am not actually buying anything? Think before you type! That is the best way to not be that sad struggling fish at the mercy of some hook.

Well friends, sadly, we have reached that point of the episode which will actually transform this into a series instead of leaving it as a single episode, since I am unable to write a small script. Oops, sorry about that! We will continue on this journey next week, where I will talk about some other interesting buzzwords you might have heard when out and about. No spoilers though, as it might ruin the fun of it! I await you all in the next episode of this series. For now, feel free to share any of your thoughts on this episode in any of our social media channels! I bid you all farewell and until next time! Bye!

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