This Week in Security

238 Articles

This Week In Security: The Facebook Leak, The YouTube Leak, And File Type Confusion

April 9, 2021 by 21 Comments

Facebook had a problem, way back in the simpler times that was 2019. Something like 533 million accounts had the cell phone number associated with the account leaked. It’s making security news this week, because that database has now been released for free in its entirety. The dataset consists of Facebook ID, cell number, name, location, birthday, bio, and email address. Facebook has pointed out that the data was not a hack or breach, but was simply scraped prior to a vulnerability being fixed in 2019.

The vulnerability was in Facebook’s contact import service, also known as the “Find Friends” feature. The short explanation is that anyone could punch a random phone number in, and get a bit of information about the FB account that claimed that number. The problem was that some interfaces to that service didn’t have appropriate rate limiting features. Combine that with Facebook’s constant urging that everyone link a cell number to their account, and the default privacy setting that lets anyone locate you by your cell number, and the data scraping was all but inevitable. The actual technique used may have been to spoof that requests were coming from the official Facebook app.

[Troy Hunt]’s Have i been pwned service has integrated this breach, and now allows searching by phone number, so go check to see if you’re one of the exposed. If you are, keep the leaked data in mind every time an email or phone call comes from someone you don’t know. Continue reading “This Week In Security: The Facebook Leak, The YouTube Leak, And File Type Confusion” →

This Week In Security: Ubiquity Update, PHP Backdoor, And Netmask

April 2, 2021 by 11 Comments

Back in January, we covered the news that Ubiquiti had a breach of undisclosed severity. One reader pointed out the compromise of a handful of devices as potentially related. With no similar reports out there, I didn’t think too much of it at the time. Now, however, a whistleblower from Ubiquiti has given Krebs the juicy details.

The “third party cloud provider” the original disclosure referred to was Amazon Web Services (AWS). According to the whistleblower, just about everything was accessible, including the keys to log in to any Ubiquiti device on the internet, so long as it was cloud enabled. The attackers installed a couple of backdoors in Ubiquiti’s infrastructure, and sent a 50 bitcoin blackmail threat. To their credit, Ubiquiti ignored the blackmail and cleaned up the mess.

To the claim that there was no evidence attackers had accessed user accounts, it seems that the database in question simply has no logging enabled. There was no evidence, because nothing was watching. So far, I’ve only seen the one report of device compromise that was potentially a result of the attack. If you had a Ubiquiti device go rogue around December 2020 – January 2021, be sure to let us know. Continue reading “This Week In Security: Ubiquity Update, PHP Backdoor, And Netmask” →

This Week In Security: XcodeSpy, Insecure SMS, And Partial Redactions

March 26, 2021 by 25 Comments

There seems to be a new trend in malware, targeting developers and their development and build processes. The appeal is obvious: rather than working to build and market a malicious application, an attacker just needs to infect a development machine. The hapless infected developers can now do the hard work to spread the malicious payload.

The newest example is XcodeSpy, discovered by a researcher who chose to remain anonymous. It works by using the Xcode IDE’s Run Script function to, well, run a script that completely backdoors your computer. The instance was found in a repackaged open source project, TabBarInteraction, but they’re just innocent victims. It was simple enough for someone to insert a script in the build process, and distribute the new, doped package. It’s probably not the only one out there, so watch out for Run Scripts with obfuscated payloads.

Continue reading “This Week In Security: XcodeSpy, Insecure SMS, And Partial Redactions” →

This Week In Security: Spectre In The Browser, Be Careful What You Clone, And Hackintosh

March 19, 2021 by 12 Comments

Google has been working on mitigations for the Spectre attack, and has made available a Proof of Concept that you can run in your browser right now. Spectre is one of the issues that kicked off the entire series of speculative execution vulnerabilities and fixes. What Google has demonstrated is that the Spectre attack can actually be pulled off in Javascript, right in the browser. Spectre is limited to reading memory allocated to the same process, and modern browsers have implemented measures like site isolation, which puts each site in a separate, sandboxed process.

These security features don’t mean that there is no practical dangers from Spectre. There are a handful of ways an attacker can run Javascript on another site, from something as simple as an interactive advertisement, to a cross-site scripting injection. Google has produced features and guidance to mitigate those dangers.

Via Bleeping Computer. Continue reading “This Week In Security: Spectre In The Browser, Be Careful What You Clone, And Hackintosh” →

This Week In Security: Text Rendering On Windows, GNU Poke, And Bitsquatting

March 5, 2021 by 27 Comments

Project Zero just unrestricted the details on CVE-2021-24093, a potentially nasty vulnerability in Windows 10’s DirectWrite, a text rendering library. The flaw got fixed in this month’s patch Tuesday roundup. The flaw is accessible in all the major browsers on Windows 10, as they use DirectWrite for font rendering. The trick here is to use a malicious font that uses some nonsense values. Those values result in a buffer allocation that is too small for complex characters such as Æ.

Because the vulnerability is a Windows library, it’s possible that an exploit would automatically work as a sandbox escape, but I haven’t seen confirmation either way. Let us know if you have some insight there.

Via Bleeping Computer

GNU Poke

The good folks at GNU have minted the 1.0 release of poke, a new binary editing tool. The real killer feature of poke is that it can interpret binary data, decoding it back into readable data structures. If you’re familiar with the way Wireshark can decode packets and give useful, organized output, it seems that poke will provide a similar function, but not limited to network traffic.

It looks like it could become a useful tool for getting a look inside otherwise opaque binaries. What poke brings is a system where you can write pretty-printing templates on the fly, which should be very useful when mapping out an unfamiliar binary. Distros will likely pick up and start packaging poke in the coming weeks, making it even easier to get and play with. Continue reading “This Week In Security: Text Rendering On Windows, GNU Poke, And Bitsquatting” →

This Week In Security: Mysterious Mac Malware, An Elegant VMware RCE, And A JSON Mess

February 26, 2021 by 10 Comments

There’s a new malware strain targeting MacOS, Silver Sparrow, and it’s unusual for a couple reasons. First, it’s one of the few pieces of malware that targets the new M1 ARM64 processors. Just a reminder, that is Apple’s new in-house silicon design. It’s unusual for a second reason — it’s not doing anything. More precisely, while researchers have been watching, the command and control infrastructure didn’t provide a payload. Silver Sparrow has been positively found on nearly 30,000 machines.

The malware also has an intentional kill switch, where the presence of a particular file triggers a complete removal of the malware package. Researchers at Red Canary point out that this package behaves very much like a legitimate program, difficult to pick out as malware. Ars Technica got an off-the-record statement from Apple, indicating that they are tracking the situation, and have revoked the developer’s certificate used to sign the malware. It’s not entirely clear whether this prevents the malware running on already compromised machines, or just stops new infections.

So who’s behind Silver Sparrow? The observed stealth mode and other complexities suggest that this is more than a simple adware or ransomware campaign. Since it was discovered before the payload was delivered, we may never know what the purpose is. It may have been a government created campaign, targeting something specific. Continue reading “This Week In Security: Mysterious Mac Malware, An Elegant VMware RCE, And A JSON Mess” →

This Week In Security: ISNs, Patch Tuesday, And Clubhouse

February 19, 2021 by 4 Comments

Let’s talk TCP. Specifically, how do the different TCP connections stay distinct, and how is a third party kept from interrupting a connection? One of the mechanisms that help accomplish this feat is the TCP sequence number. Each of the two endpoints of a TCP connection tracks an incrementing 32-bit number, corresponding to the bytes sent in the connection. It’s handy, because each side can use that value to track what parts of the data stream they have received. On missing packets, a message can be sent requesting bytes 7-15 to be resent, for instance.

Each side of the connection sets their own Initial Sequence Number (ISN), and it’s important that this number is unique, as collisions can cause stream confusion. That statement should make your security spidey sense tingle. If a collision can cause problems when it happens by chance, what can a hacker do with it intentionally? Potentially quite a bit. Knowing the current sequence number, as well as a couple other pieces of information, a third party can close a TCP stream or even inject data. The attack has been around for years, originally known as the Mitnick Attack. It was originally possible because TCP implementations used a simple counter to set the ISN. Once the security ramifications of this approach were understood, the major implementations moved to a random number generation for their ISNs.

Now to this week’s story: researchers at Forescout took the time to check 11 TCP/IP stacks for vulnerability to the old Mitnick Attack (PDF Whitepaper). Of the eleven embedded stacks texted, nine have serious weaknesses in their ISN generation. Most of the vulnerable implementations use a system time value as their ISN, while several use a predictable pseudorandom algorithm that can be easily reversed.

CVEs have been assigned, and vendors notified of “NUMBER:JACK”, Forescout’s name for the research. Most of the vulnerable software already has patches available. The problem with embedded systems is that they often never get security updates. The vulnerable network stacks are in devices like IP cameras, printers, and other “invisible” software. Time will tell if this attack shows up as part of a future IoT botnet.
Continue reading “This Week In Security: ISNs, Patch Tuesday, And Clubhouse” →