This Week In Security: Loop DOS, Flipper Responds, And More!

March 22, 2024 by 8 Comments

Here’s a fun thought experiment. UDP packets can be sent with an arbitrary source IP and port, so you can send a packet to one server, and could aim the response at another server. What happens if that response triggers another response? What if you could craft a packet that continues that cycle endlessly? That is essentially the idea behind Loop DoS (Denial of Service).

This unique avalanche of packets has been managed using specific implementations of several different network services, like TFTP, DNS, and NTP. There are several CVEs being used to track the issue, but CVE-2024-2169 is particularly odd, with the description that “Implementations of UDP application protocol are vulnerable to network loops.” This seems to be a blanket CVE for UDP, which is particularly inappropriate given that the first DoS of this sort was first reported in 2009 at the latest.

More details are available in a Google Doc. There some interesting tidbits there, like the existence of cross-protocol loops, and several legacy protocols that are vulnerable by design. The important thing to remember here is you have to have an accessible UDP port for this sort of attack to take place, so if you’re not using it, firewall it.

Flipper Flips Back

We’ve covered the saga of the Flipper Zero vs the Canadian government, in the context of car theft. The short version is that Canada has seen an uptick of car thefts from organized crime. Rather than meaningfully dealing with this problem, the Canadian government went looking for scapegoats, and found the Flipper Zero.

Well now, Flipper has responded, and put simply, the message is “stop the madness”. There has never been a confirmed case of using a flipper to steal a car, and it’s very unlikely it’s ever happened. On a modern car with proper rolling-code security, it’s not meaningfully possible to use the Flipper Zero for the theft. The two primary ways criminals actually steal cars are with dedicated keyfob repeaters and CAN bus hackers.

There is a petition to sign, and for Canadians, Flipper suggests contacting your local member of parliament. Continue reading “This Week In Security: Loop DOS, Flipper Responds, And More!” →

This Week In Security: Forksquatting, RustDesk, And M&Ms

March 1, 2024 by 14 Comments

Github is struggling to keep up with a malware campaign that’s a new twist on typosquatting. The play is straightforward: Clone popular repositories, add malware, and advertise the forks as the original. Some developers mistake the forks for the real projects, and unintentionally run the malware. The obvious naming choice is forksquatting, but the researchers at apiiro went with the safer name of “Repo Confusion”.

The campaign is automated, and GitHub is aware of it, with the vast majority of these malicious repositories getting removed right away. For whatever reason, the GitHub algorithm isn’t catching all of the new repos. The current campaign appears to publishing millions of forks, using code from over 100,000 legitimate projects. It’s beginning to seem that the squatting family of attacks are here to stay.

RustDesk and Odd Certificates

The RustDesk remote access software is interesting, as it’s open source, allows self-hosting, and written in Rust. I’ve had exploring RustDesk as a todo item for a long time, but a bit of concerning drama has just finished playing out. A user pointed out back in November that a test root certificate was installed as part of the RustDesk installation. That root cert is self-signed with SHA1. There is also concern that the RustDesk binaries are signed with a different certificate.

There have been new events since then. First, there was a Hacker News thread about the issue earlier this month. The next day, CVE-2024-25140 was registered with NIST, ranking an insane CVE 9.8 CVSS. Let’s cut through some FUD and talk about what’s really going on.

Continue reading “This Week In Security: Forksquatting, RustDesk, And M&Ms” →

This Week In Security: Gitlab, VMware, And PixeFAIL

January 19, 2024 by 3 Comments

There’s a Gitlab vulnerability that you should probably pay attention to. Tracked as CVE-2023-7028, this issue allows an attacker to specify a secondary email during a the password reset request. Only one email has to match the one on record, but the password reset link gets sent to both emails. Yikes!

What makes this worse is there is already a Proof of Concept (PoC) released, and it’s a trivial flaw. In an HTTP/S post containing the password reset request, just include two email addresses. Thankfully, a fix is already out. Versions 16.7.2, 16.6.4, and 16.5.6 contain this patch, as well as fixes for a flaw that allowed sneaking unauthorized changes into a previously approved merge request, and an issue with Slack and Mattermost where slash commands could be spoofed.

VMware

We don’t want to over-dramatise this vulnerability, but VMware is calling it an emergency. This one affects VMware vRealize and Aria Automation. According to the the CVSS calculator, it’s a low complexity network flaw, but does require at least some privileges. Hopefully more information will come out about this vulnerability, but for now that’s about all we know.

Continue reading “This Week In Security: Gitlab, VMware, And PixeFAIL” →

This Week In Security: Minecraft Fractureiser, MOVEit, And Triangulation

June 9, 2023 by 2 Comments

Modded Minecraft is having a security moment, to match what we’ve seen in the Python and JavaScript repositories over the last few months. It looks like things started when a handful of burner accounts uploaded malicious mods to Curseforge and Bukkit. Those mods looked interesting enough, that a developer for Luna Pixel Studios (LPS) downloaded one of them to test-run. After the test didn’t pan out, he removed the mod, but the malicious code had already run.

Where this gets ugly is in how much damage that one infection caused. The virus, now named fractureiser, installs itself into every other Minecraft-related .jar on the compromised system. It also grabs credentials, cookies, cryptocurrency addresses, and the clipboard contents. Once that information was exfiltrated from the LPS developer, the attacker seems to have taken manual actions, using the purloined permissions to upload similarly infected mod files, and then marking them archived. This managed to hide the trapped files from view on the web interface, while still leaving them exposed when grabbed by the API. Once the malware hit a popular developer, it began to really take off.

It looks like the first of the malicious .jar files actually goes all the way back to mid-April, so it may take a while to discover all the places this malware has spread. It was first noticed on June 1, and investigation was started, but the story didn’t become public until the 7th. Things have developed rapidly, and the malware fingerprints has been added to Windows Defender among other scanners. This helps tremendously, but the safe move is to avoid downloading anything Minecraft related for a couple days, while the whole toolchain is inspected. If it’s too late and you’ve recently scratched that voxel itch, it might be worth it to take a quick look for Indicators of Compromise (IoCs).

Continue reading “This Week In Security: Minecraft Fractureiser, MOVEit, And Triangulation” →

This Week In Security: .zip Domains, Zip Scanning

May 19, 2023 by 17 Comments

The world may not be ready, but the .zip Top Level Domain (TLD) is here. It’s a part of the generic TLD category, which was expanded to allow applications for custom TLDs. Google has led the charge, applying for 101 such new TLDs, with .zip being one of the interesting ones. Public registration for .zip domains has been open for a couple weeks, and some interesting domains have been registered, like update.zip, installer.zip, and officeupdate.zip.

The obvious question to ask is whether this new TLD can be abused for scamming and phishing purposes. And the answer is yes, sure it can. One of the trickiest ways is to use the AT symbol @ in a URL, which denotes user info at the beginning of the URL. It usually is used to include a username and password, like http://username:password@192.168.1.1/. That is pretty obvious, but what about https://google.com@bing.com? Still looks weird. The catch that really prevents this technique being abused is that slashes are disallowed in user data, so a abusive URL like https://google.com∕gmail∕inbox@bing.com is right out.

Except, take a look at that last link. Looks like it has slashes in it, so it should take you to google, and ignore the AT symbol. But it doesn’t, it goes to Bing. You may have guessed, it’s Unicode shenanigans again. Those aren’t slashes, they’re U2215, the division slash. And that means that a .zip TLD could be really sneaky, if the apparent domain is one you trust. Continue reading “This Week In Security: .zip Domains, Zip Scanning” →

This Week In Security: Github, Google, And Realtek

February 3, 2023 by 4 Comments

GitHub Desktop may have stopped working for you yesterday, Febuary 2nd. The reason was an unauthorized access to some decidedly non-public repositories. The most serious bit of information that escaped was code signing certificates, notably used for GitHub Desktop and Atom. Those certificates were password protected, so it’s unlikely they’ve been abused yet. Even so, Github is taking the proper steps of revoking those certificates.

The only active certificate that was revoked was used for signing the Mac releases of GitHub Desktop, so quite a few older versions of that software is no longer easily installed. If nothing else, it’s a reminder that even a project with a well run security team can have problems.

Sh1mmer-ing Chromebooks

There’s a new, clever attack on the Chromebook, specifically with the goal of unenrolling the device from an educational organization. And the “vulnerability” is a documented feature, the RMA Shim. That’s a special boot loader target that contains a valid signature, but allows the booting of other code, intended for troubleshooting and fixing devices in a repair center. Quite a few of those images have leaked, and Sh1mmer combines the appropriate image with a boot menu with some interesting options.

The first is unenrolling, so the device will act like a privately owned computer. This gets rid of content blocks and allows removing extensions. But wait, there’s more. Like rooting the device, a raw Bash terminal, and re-enabling developer mode. Now, as far as we can tell, this doesn’t *directly* break device encryption, but it’s likely that the RMA shim could be abused to tamper with the device’s filesystem. Meaning that the leak of a bunch of signed shims is a big problem for device security. If you use a Chromebook, it might be time to do some research on whether that model’s shim has been leaked. Continue reading “This Week In Security: Github, Google, And Realtek” →

This Week In Security: Zimbra, Lockbit 2, And Hacking NK

February 11, 2022 by 9 Comments

Unknown attackers have been exploiting a 0-day attack against the Zimbra e-mail suite. Researchers at Volexity first discovered the attack back in December of last year, detected by their monitoring infrastructure. It’s a cross-site scripting (XSS) exploit, such that when opening a malicious link, the JavaScript running on the malicious page can access a logged-in Zimbra instance. The attack campaign uses this exploit to grab emails and attachments and upload them to the attackers. Researchers haven’t been able to positively identify what group is behind the attacks, but a bit of circumstantial evidence points to a Chinese group. That evidence? Time zones. The attacker requests all use the Asia/Hong_Kong time zone, and the timing of all the phishing emails sent lines up nicely with a work-day in that time zone.

Zimbra has responded, confirming the vulnerability and publishing a hotfix for it. The campaign seems to have been targeted specifically against European governments, and various media outlets. If you’re running a Zimbra instance, make sure you’re running at least 8.8.15.1643980846.p30-1.

LockBit 2.0

Because security professionals needed something else to keep us occupied, the LockBit ransomware campaign is back for a round two. This is another ransomware campaign run in the as-a-Service pattern — RAAS. LockBit 2 has caught enough attention, that the FBI has published a FLASH message (PDF) about it. That’s the FBI Liaison Alert System, in the running for the worst acronym. (Help them figure out what the “H” stands for in the comments below!)

Like many other ransomware campaigns, LockBit has a list of language codes that trigger a bail on execution — the Eastern European languages you would expect. Ransomware operators have long tried not to poison their own wells by hitting targets in their own back yards. This one is being reported as also having a Linux module, but it appears that is limited to VMWare ESXi virtual machines. A series of IoCs have been published, and the FBI are requesting any logs, ransom notes, or other evidence possibly related to this campaign to be sent to them if possible. Continue reading “This Week In Security: Zimbra, Lockbit 2, And Hacking NK” →