This Week In Security: Signal, WhatsApp, Oauth Fishing, And More State-Sponsored Attacks

A bug was recently fix in Signal that allowed a caller to force a call connection without any user interaction on the receiving side. We’ve seen this sort of problem in other chat applications, most recently the Zoom debacle.

The Signal client uses the same function to connect an outgoing call as an incoming call. This bit of code re-use allows a malicious client to initiate a call, and then send the “Accept Call” message. Because of the code re-use, this message triggers the same code as the accept call button on the receiving side. It’s as if the attacker uses reverse psychology to trick the other client into connecting.

It seems this bug only affected the Android client, and didn’t trigger a video call. It’s unclear whether the bug was discovered and exploited before it was fixed, but now that it has been announced, be sure to get Signal up to date. Continue reading “This Week In Security: Signal, WhatsApp, Oauth Fishing, And More State-Sponsored Attacks”

This Week In Security: Is RSA Finally Broken? The Push For Cloud Accounts, Encrypted DNS, And More Mobile Mayhem

Ever wondered what “cyberwar” looks like? Apparently it’s a lot of guessing security questions and changing passwords. It’s an interesting read on its own, but there are some interesting clues if you read between the lines. A General in the know mentioned that Isis:

clicked on something or they did something that then allowed us to gain control and then start to move.

This sounds very similar to stories we’ve covered in the past, where 0-days are used to compromise groups or individuals. Perhaps the NSA supplied such an exploit, and it was sent in a phishing attack. Through various means, the U.S. team quietly compromised systems and collected credentials.

The article mentions something else interesting. Apparently the targets of this digital sting had also been compromising machines around the world, and using those machines to manage their efforts. The decision was made by the U.S. team to also compromise those machines, in order to lock out the Isis team. This might be the most controversial element of the story. Security researchers have wanted permission to do this for years. How should the third parties view these incursions?

The third element that I found particularly interesting was the phase 2 attack. Rather than outright delete, ban, and break Isis devices and accounts, the U.S. team installed persistent malware that emulated innocuous glitches. The internet connection is extremely laggy on certain days, certain websites simply don’t connect, and other problems. These are the sort of gremlins that networking pros spend all day trying to troubleshoot. The idea that it’s intentional gives me one more thing to worry about. Continue reading “This Week In Security: Is RSA Finally Broken? The Push For Cloud Accounts, Encrypted DNS, And More Mobile Mayhem”

This Week In Security: Patch Monday Mysteries, CentOS 8 And CentOS Stream, Russian Surveillance, And CSRF

So first off this week is something of a mystery. Microsoft released an out-of-cycle patch for Internet Explorer. The exploitability assessment from Microsoft indicates that this bug is under active exploitation, but not many details are available. Let’s take a look at what information has been released, and see what we can learn.

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer.

It’s a remote code execution vulnerability, it affects Internet Explorer, it’s in the scripting engine, and it happens due to objects in memory being mishandled. We could take some guesses, but later in this document we’re given a few other clues. The workaround is to disable jscript.dll, and the impact is limited, as jscript9.dll is the default JavaScript engine. jscript.dll is apparently a legacy JavaScript engine that a website can request.

“Jscript” is what Microsoft called their shameless copy implementation of JavaScript. The older jscript.dll seems to be present in newer versions of Internet Explorer for compatibility reasons. So it’s a problem in how the older JavaScript library handles objects. Any website can request this legacy engine, so the attack vector is basically unlimited.

The urgency implied by the out-of-cycle patch, combined with the otherwise eery silence surrounding this patch, suggests this 0-day was possibly being used in a targeted attack. We hope the details will eventually be revealed.

CentOS 8 and CentOS Stream

CentOS 8 was released this week, the community repackage of Red Hat Enterprise Linux (RHEL) 8. In 2014, Red Hat announced that CentOS was officially becoming a Red Hat sponsored project. This week, CentOS Stream was also announced.

The Fedora distribution has long served as a test-bed for upcoming RHEL releases, with RHEL 8 being based on Fedora 28. CentOS Stream will serve as a “midstream” distribution, a rolling release that pulls updates from Fedora, and will eventually become future RHEL/CentOS releases. It remains to be seen exactly how far ahead of the main CentOS distribution Stream will stay. A long-standing problem with CentOS is that by the time a release hits end-of-life, some of the software versions are very old. Even though security fixes are quickly backported to these older versions, there are security issues that arise as a result. For example, CentOS 7 contains PHP 5.4 with no official path to installing a newer version of PHP. WordPress now requires PHP 5.6.20 as the oldest supported PHP version. Red Hat may backport fixes to PHP 5.4, but that doesn’t help the out-of-date installs of WordPress, running on otherwise up-to-date CentOS machines.

Hopefully CentOS Stream will provide the much needed middle-ground between the bleeding-edge pace of Fedora, and the frustratingly slow march of CentOS/RHEL.

Russian Surveillance

A Nokia employee accidentally backed up a company drive to his home storage device, which was unintentionally Internet accessible. The data contained on this drive was detailed information on Russia’s SORM (System for Operative Investigative Activities), the government’s wiretapping program. The amount of data revealed is staggering, 1.7 terabytes. Passwords, administrative URLs, and even precise physical locations were included. The breadth of information makes one wonder if it was actually an accident, or if this was intended to be another Snowden style data leak. Just an aside, it’s not clear that the revealed wiretapping effort is as broad or onerous as the one Snowden revealed.

PHPMyAdmin CSRF

Running PHPMyAdmin on one of your servers? You should probably go update it. Version 4.9.1 was released on Saturday the 21st, and contains a fix for CVE-2019-12922. This vulnerability is a Cross Site Request Forgery, or CSRF. A CSRF attack can be as simple as an image link on one site, that links to another site, and triggers an action on that second site. Let’s look at the PHPMyAdmin example:

img src="
http://server/phpmyadmin/setup/index.php?page=servers&mode=remove&id=1";
style="display:none;"

A hidden image will actually trigger an HTTP GET request, which asks for the server’s page, and tries to remove the first entry. If a user is logged in to the PHPMyAdmin server that the link is targeting, the command will silently complete. This is one of the reasons that HTTP GET requests should never make state changes, and only ever retrieve information. An HTTP POST message is much harder to generate in this way, though not impossible.

This Week In Security: Zeroconf Strikes Again, Lastpass Leaks Your Last Password, And All Your Data Is Belong To Us

VoIP cameras, DVRs, and other devices running the Web Services Dynamic Discovery (WSDD) protocol are being used in a new type of DDoS attack. This isn’t the first time a zeroconf service has been hijacked as part of a DDoS, as UPnP has also been abused in similar ways.

Feel like alphabet soup yet? A Denial of Service attack is one where the target is simply made unavailable, rather than actually compromised. The classic example of this is the SYN flood, where an attacker would open hundreds of connections to a web server at once, exhausting the server’s resources and interrupting legitimate use of that server. As mitigations for these attacks were developed (SYN Cookies, for example), DoS attacks were replaced by Distributed Denial of Service (DDOS) attacks. Rather than attack a weakness on the target machine, like available RAM or CPU cycles, a DDoS generally targets available network bandwidth by hitting the target website from many, many locations at once. No clever software tricks can help when your Internet connection is fully saturated with junk traffic. Continue reading “This Week In Security: Zeroconf Strikes Again, Lastpass Leaks Your Last Password, And All Your Data Is Belong To Us”

This Week In Security: Simjacker, Microsoft Updates, Apple Vs Google, Audio DeepFakes, And NetCAT

We often think of SIM cards as simple data storage devices, but in reality a SIM card is a miniature Universal integrated circuit card, or smart card. Subscriber data isn’t a simple text string, but a program running on the smart cards tiny processor, acting as a hardware cryptographic token. The presence of this tiny processor in everyone’s cell phone was eventually put to use in the form of the Sim application ToolKit (STK), which allowed cell phone networks to add services to very basic cell phones, such as mobile banking and account management.

Legacy software running in a place most of us have forgotten about? Sounds like it’s ripe for exploitation. The researchers at Adaptive Mobile Security discovered that exploitation of SMS messages has been happening for quite some time. In an era of complicated and sophisticated attacks, Simjacker seems almost refreshingly simple. An execution environment included on many sim cards, the S@T Browser, can request data from the cell phone’s OS, and even send SMS messages. The attacker simply sends an SMS to this environment containing instructions to request the phones unique identifier and current GPS location, and send that information back in another SMS message.

It’s questionable whether there is actually an exploit here, as it seems the S@T Browser is just insecure by design. Either way, the fact that essentially anyone can track a cell phone simply by sending a special SMS message to that phone is quite a severe problem. Continue reading “This Week In Security: Simjacker, Microsoft Updates, Apple Vs Google, Audio DeepFakes, And NetCAT”

Can You Really Use The Raspberry Pi 4 As A Desktop Machine?

When the Raspberry Pi 4 was released, many looked at the dual micro HDMI ports with disdain. Why would an SBC like the Raspberry Pi need two HDMI ports? The answer was that the Pi 4 is finally fast enough to work as a desktop replacement, and the killer feature (for many of us) for a desktop is multiple monitors.

Now I know what many of you are thinking. There’s no way a $35, or even $55, credit-card-sized computer can replace a $1000+ desktop machine, right? Right? Of course not, but at the same time, yes, yes it can. So I tried to use the Pi as a desktop replacement for a week, and it worked. In fact, this article has been written almost entirely on the Pi 4 with 4 GB of memory, as well as a couple of my recent security columns. I could definitely continue working with the Pi as my daily driver for that purpose.

There are a few points of order to cover first. Initial reviews were based on the June 20th release of Raspbian, which in turn was based on the pre-release Debian Buster. Since then, Buster has released. Fixes that were queued up have landed now that the release freeze has ended. A new Raspbian image was released on July 10, and many of the initial release issues have been fixed.
Continue reading “Can You Really Use The Raspberry Pi 4 As A Desktop Machine?”

This Week In Security: Mass IPhone Compromise, More VPN Vulns, Telegram Leaking Data, And The Hack Of @Jack

In a very mobile-centric installment, we’re starting with the story of a long-running iPhone exploitation campaign. It’s being reported that this campaign was being run by the Chinese government. Attack attribution is decidedly non-trivial, so let’s be cautious and say that these attacks were probably Chinese operations.

In any case, Google’s Project Zero was the first to notice and disclose the malicious sites and attacks. There were five separate vulnerability chains, targeting iOS versions 10 through 12, with at least one previously unknown 0-day vulnerability in use. The Project Zero write-up is particularly detailed, and really documents the exploits.

The payload as investigated by Project Zero doesn’t permanently install any malware on the device, so if you suspect you could have been compromised, a reboot is sufficient to clear you device.

This attack is novel in how sophisticated it is, while simultaneously being almost entirely non-targeted. The malicious code would run on the device of any iOS user who visited the hosting site. The 0-day vulnerability used in this attack would have a potential value of over a million dollars, and these high value attacks have historically been more targeted against similarly high-value targets. While the websites used in the attack have not been disclosed, the sites themselves were apparently targeted at certain ethnic and religious groups inside China.

Once a device was infected, the payload would upload photos, messages, contacts, and even live GPS information to the command & control infrastructure. It also seems that Android and Windows devices were similarly targeted in the same attack.

Telegram Leaking Phone Numbers

“By default, your number is only visible to people who you’ve added to your address book as contacts.” Telegram, best known for encrypted messages, also allows for anonymous communication. Protesters in Hong Kong are using that feature to organize anonymously, through Telegram’s public group messaging. However, a data leak was recently discovered, exposing the phone numbers of members of these public groups. As you can imagine, protesters very much want to avoid being personally identified. The leak is based on a feature — Telegram wants to automatically connect you to other Telegram users whom you already know.

By default, your number is only visible to people who you’ve added to your address book as contacts.

Telegram is based on telephone numbers. When a new user creates an account, they are prompted to upload their contact list. If one of the uploaded contacts has a number already in the Telegram system, those accounts are automatically connected, causing the telephone numbers to become visible to each other. See the problem? An attacker can load a device with several thousand phone numbers, connect it to the Telegram system, and enter one of the target groups. If there is a collision between the pre-loaded contacts and the members of the group, the number is outed. With sufficient resources, this attack could even be automated, allowing for a very large information gathering campaign.

In this case, it seems such a campaign was carried out, targeting the Hong Kong protesters. One can’t help but think of the first story we covered, and wonder if the contact data from compromised devices was used to partially seed the search pool for this effort.

The Hack of @Jack

You may have seen that Twitter’s CEO, Jack [@Jack] Dorsey’s Twitter account was hacked, and a series of unsavory tweets were sent from that account. This seems to be a continuing campaign by [chucklingSquad], who have also targeted other high profile accounts. How did they manage to bypass two factor authentication and a strong password? Cloudhopper. Acquired by Twitter in 2010, Cloudhopper is the service that automatically posts a user’s SMS messages to Twitter.

Rather than a username and password, or security token, the user is secured only by their cell phone number. Enter the port-out and SIM-swap scams. These are two similar techniques that can be used to steal a phone number. The port-out scam takes advantage of the legal requirement for portable phone numbers. In the port-out scam, the attacker claims to be switching to a new carrier. A SIM-swap scam is convincing a carrier he or she is switching to a new phone and new SIM card. It’s not clear which technique was used, but I suspect a port-out scam, as Dorsey hadn’t gotten his cell number back after several days, while a SIM swap scam can be resolved much more quickly.

Google’s Bug Bounty Expanded

In more positive news, Google has announced the expansion of their bounty programs. In effect, Google is now funding bug bounties for the most popular apps on the Play store, in addition to Google’s own code. This seems like a ripe opportunity for aspiring researchers, so go pick an app with over 100 million downloads, and dive in.

An odd coincidence, that 100 million number is approximately how many downloads CamScanner had when it was pulled from the Play store for malicious behavior. This seems to have been caused by a third party advertisement library.

Updates

Last week we talked about Devcore and their VPN Appliance research work. Since then, they have released part 3 of their report. Pulse Secure doesn’t have nearly as easily exploited vulnerabilities, but the Devcore team did find a pre-authentication vulnerability that allowed reading arbitraty data off the device filesystem. As a victory lap, they compromised one of Twitter’s vulnerable devices, reported it to Twitter’s bug bounty program, and took home the highest tier reward for their trouble.