Security Hacks

1443 Articles

This Week In Security: Open Source C2, Raptor Trains, And End To End Encryption

September 20, 2024 by 14 Comments

Open Source has sort of eaten everything in software these days. And that includes malware, apparently, with open source Command and Control (C2) frameworks like Sliver and Havoc gaining traction. And of course, this oddball intersection of Open Source and security has intrigued at least one security researcher who has found some interesting vulnerabilities.

Before we dive into what was found, you may wonder why open source malware tools exist. First off, trustworthy C2 servers are quite useful for researchers, who need access to such tools for testing. Then there is Red Teaming, where a security professional launches a mock attack against a target to test its defenses. A C2 is often useful for education and hobby level work, and then there are the true criminals that do use these Open Source tools. It takes all types.

A C2 system consists of an agent installed on compromised systems, usually aiming for stealth. These agents connect to a central server, sending information and then executing any instructions given. And finally there’s a client, which is often just a web interface or even a command line interface.

Now what sort of fun is possible in these C2 systems? Up first is Sliver, written in Go, with a retro command line interface. Sliver supports launching Metasploit on compromised hosts. Turns out, it accidentally supported running Metasploit modules against the server’s OS itself, leading to an easy remote shell from an authenticated controller account.

Havoc has a fancy user interface for the clients, and also a command injection flaw. A service name field gets used to generate a shell command, so you’re only a simple escape away from running commands. That’s not quite as useful as the API that failed open when a bad username/password was given. Oops. Continue reading “This Week In Security: Open Source C2, Raptor Trains, And End To End Encryption” →

This Week In Security: Malicious Rollback, WHOIS, And More

September 13, 2024 by 4 Comments

It’s time to talk about Microsoft’s patch Tuesday, and the odd vulnerability rollback that happened. CVE-2024-43491 has caught some attention, as it’s a 9.8 on the CVSS scale, is under active exploitation, and results in Remote Code Execution (RCE). Yikes, it sounds terrible!

First off, what actually happened? The official statement is that “build version numbers crossed into a range that triggered a code defect”. We don’t know the exact details, but it’s something like an unsigned integer that was interpreted as a signed integer. A build number could have rolled over 32767, and what was intended to be 32768 or higher suddenly became −32767. Lots of “if greater than or equal” logic breaks down in that situation. Because of a logic flaw like this, certain versions of Windows 10 were unintentionally opting out of some historical security fixes.

And that’s where the high CVSS score and active exploitation descriptor comes from. This is simply the highest score of the resurgent flaws, and an acknowledgement that they have been exploited in the past. The good news is that this only applies to Windows 10 build 1507, so either the original install without any of the major updates installed, or one of the Windows 10 Enterprise Long-Term Servicing Branch (LTSB) versions. It seems that the March 2024 monthly security update introduced the problem, and it wasn’t fixed until this month’s updates. Continue reading “This Week In Security: Malicious Rollback, WHOIS, And More” →

This Week In Security: EUCLEAK, Revival Hijack, And More

September 6, 2024 by 5 Comments

[Thomas Roche] of NinjaLab is out with EUCLEAK, (pdf) a physical attack against Infineon security microcontrollers, and the security tokens that contain them. The name is a portmanteau of Euclidean and leak. And no surprise, it’s a data leak in some implementations of the Extended Euclidean Algorithm (EEA), a component of an Elliptical Curve Digital Signature Algorithm (ECDSA).

OK, time to step back. Infineon microcontrollers are the digital smart parts inside popular security tokens like the Yubikey 5, some Java smart cards, and even the Infineon TPMs. These devices all serve a similar purpose. They store one or more secret keys, and are guaranteed to never disclose those keys. Instead, they use their secret keys to do cryptographic functions, like ECDSA signatures, and output the result. There’s even a special set of tests, the Common Criteria, that are intended to backstop these guarantees. What’s interesting is that an otherwise excellent product like the Yubikey 5, that passes all these auditing and certification processes, is still vulnerable.

The actual attack is to perform ECDSA signatures while monitoring the physical chip with an electromagnetic probe. This tiny directional antenna can pick up on EM noise generated by the microprocessor. That EM noise leaks timing information about the internal state of the cryptography, and the secret key can be derived as a result.

This process does require physical access to the token for several minutes. To get useful readings, the plastic case around the security token does need to be disassembled to get the probe close enough to pick up signals. From there it’s at least an hour of post-processing to actually get the key. And most of these security tokens intentionally make the disassembly process rather difficult. The point isn’t that it’s impossible to open up, but that it’s impossible not to notice that your token has been tampered with. Continue reading “This Week In Security: EUCLEAK, Revival Hijack, And More” →

This Week In Security: The Rest Of The IPv6 Story, CVE Hunting, And Hacking The TSA

August 30, 2024 by 2 Comments

We finally have some answers about the Windows IPv6 vulnerability — and a Proof of Concept! The patch was a single change in the Windows TCP/IP driver’s Ipv6pProcessOptions(), now calling IppSendError() instead of IppSendErrorList(). That’s not very helpful on its own, which is why [Marcus Hutchins]’s analysis is so helpful here. And it’s not an easy task, since decompiling source code like this doesn’t give us variable names.

The first question that needs answered is what is the list in question? This code is handling the option field in incoming IPv6 packets. The object being manipulated is a linked list of packet structs. And that linked list is almost always a single member list. When calling IppSendErrorList() on a list with a single member, it’s functionally equivalent to the IppSendError() in the fixed code. The flaw must be in the handling of this list with multiple members. The only way to achieve that criteria is to send a lot of traffic at the machine in question, so it can’t quite keep up with processing packets one at a time. To handle the high throughput, Windows will assemble incoming packets into a linked list and process them in batch.

So what’s next? IppSendErrorList(), takes a boolean and passes it on to each call of IppSendError(). We don’t know what Microsoft’s variable name is, but [Marcus] is calling it always_send_icmp, because setting it to true means that each packet processed will generate an ICMP packet. The important detail is that IppSendError() can have side effects. There is a codepath where the packet gets reverted, and the processing pointer is set back to the beginning of the packet. That’s fine for the first packet in the list, but because the function processes errors on the entire list of packets, the state of the rest of those packets is now much different from what is expected.

This unexpected but of weirdness can be further abused through IPv6 packet fragmentation. With a bit of careful setup, the reversion can cause a length counter to underflow, resulting in data structure corruption, and finally jumping code execution into the packet data. That’s the Remote Code Execution (RCE). And the good news, beyond the IPv6-only nature of the flaw, is that so far it’s been difficult to actually pull the attack off, as it relies on this somewhat non-deterministic “packet coalescing” technique to trigger the flaw.

Continue reading “This Week In Security: The Rest Of The IPv6 Story, CVE Hunting, And Hacking The TSA” →

This Week In Security: Crash Your IPhone, Hack Your Site, And Bluetooth Woes

August 23, 2024 by 6 Comments

There have been some hilarious issues on mobile devices over the years. The HTC Dream had a hidden shell that was discovered when a phone rebooted after sending a text containing just the word “reboot”. iOS has gotten in on the fun from time to time, and this time it’s ""::. Type the double quotes, a colon, and any other character, and Apple’s Springboard service crashes.

Another hacker dug in a bit, and realized that Springboard is trying to jump execution to a null pointer, leading to a crash. It’s very odd that user input breaks the query parser badly enough to jump to null like that. There are a couple interesting questions that we have to ask. Given that the crash trigger is quite flexible, "anything goes":x, is it possible to manipulate that function pointer to be something other than null? And perhaps more importantly, why is the code crashing, instead of an invalid address error as one would expect from a Pointer Authentication Code (PAC) violation? Regardless, the bug seems to be fixed in the latest iOS 18 builds.

Continue reading “This Week In Security: Crash Your IPhone, Hack Your Site, And Bluetooth Woes” →

This Week In Security: Three Billion SS Numbers, IPv6 RCE, And Ring -2

August 16, 2024 by 3 Comments

You may have heard about a very large data breach, exposing the Social Security numbers of three billion individuals. Now hang on. Social Security numbers are a particularly American data point, and last time we checked there were quite a few Americans shy of even a half of a billion’s worth. As [Troy Hunt] points out, there are several things about this story that seem just a bit odd.

First up, the claim is that this is data grabbed from National Public Data, and there’s even a vague notice on their website about it. NPD is a legitimate business, grabbing data on as many people as possible, and providing services like background checks and credit checks. It’s not impossible that this company has records on virtually every citizen of the US, UK, and Canada. And while that’s far less than 2.9 billion people, it could feasibly add up to 2.9 billion records as was originally claimed.

The story gets strange as we consider the bits of data that have been released publicly, like a pair of files shared with [Troy] that have names, birthdays, addresses, phone numbers, and social security numbers. Those had a total of 2.69 billion records, with an average of 3 records for each ID number. That math is still just a little weird, since the US has to date only generated 450 million SSNs and change.

So far all we have are partial datasets, and claims on the Internet. The story is that there’s a grand total of 4 TB of data once uncompressed. The rest of the details are unclear, and it’s likely to take some time for the rest of the story to come out. Continue reading “This Week In Security: Three Billion SS Numbers, IPv6 RCE, And Ring -2” →

Can You Hack The RP2350? There’s $10,000 On The Line

August 12, 2024 by 63 Comments

The Raspberry Pi Foundation had their new RP2350 chip audited by Hextree.io, and now, both companies want to see if you can hack it. Just to prove that they’re serious, they’re putting out a $10,000 bounty. Can you get inside?

The challenge to hack the chip is simple enough. You need to dump a secret that is hidden at OTP ROW 0xc08. It’s 128 bits long, and it’s protected in two ways—by the RP2350’s secure boot and by OTP_DATA_PAGE48_LOCK1. Basically, the chip security features have been activated, and you need to get around them to score the prize.

The gauntlet was thrown down ahead of DEF CON, where the new chip was used in the event badges. Raspberry Pi and Hextree.io invited anyone finding a break to visit their booth in the Embedded Systems Village. It’s unclear at this stage if anyone claimed the bounty, so we can only assume the hunt remains open. It’s been stated that the challenge will run until 4 PM UK time on September 7th, 2024.

Hacking microcontrollers is a tough and exacting art. The GitHub repo provides full details on what you need to do, with the precise rules, terms, and conditions linked at the bottom. You can also watch the challenge video on Hextree.io.