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Analyzed 3 days ago. based on code collected 3 days ago.
Posted 8 days ago by nore...@blogger.com (ClassicHasClass)
Ars Technica is reporting an interesting attack that uses a side-channel exploit in the Intel Haswell branch translation buffer, or BTB (kindly ignore all the political crap Ars has been posting lately; I'll probably not read any more articles of ... [More] theirs until after the election). The idea is to break through ASLR, or address space layout randomization, to find pieces of code one can string together or directly attack for nefarious purposes. ASLR defeats a certain class of attacks that rely on the exact address of code in memory. With ASLR, an attacker can no longer count on code being in a constant location. Intel processors since at least the Pentium use a relatively simple BTB to aid these computations when finding the target of a branch instruction. The buffer is essentially a dictionary with virtual addresses of recent branch instructions mapping to their predicted target: if the branch is taken, the chip has the new actual address right away, and time is saved. To save space and complexity, most processors that implement a BTB only do so for part of the address (or they hash the address), which reduces the overhead of maintaining the BTB but also means some addresses will map to the same index into the BTB and cause a collision. If the addresses collide, the processor will recover, but it will take more cycles to do so. This is the key to the side-channel attack. (For the record, the G3 and the G4 use a BTIC instead, or a branch target instruction cache, where the table actually keeps two of the target instructions so it can be executing them while the rest of the branch target loads. The G4/7450 ("G4e") extends the BTIC to four instructions. This scheme is highly beneficial because these cached instructions essentially extend the processor's general purpose caches with needed instructions that are less likely to be evicted, but is more complex to manage. It is probably for this reason the BTIC was dropped in the G5 since the idea doesn't work well with the G5's instruction dispatch groups; the G5 uses a three-level hybrid predictor which is unlike either of these schemes. Most PowerPC implementations also have a return address stack for optimizing the blr instruction. With all of these unusual features Power ISA processors may be vulnerable to a similar timing attack but certainly not in the same way and probably not as predictably, especially on the G5 and later designs.) To get around ASLR, an attacker needs to find out where the code block of interest actually got moved to in memory. Certain attributes make kernel ASLR (KASLR) an easier nut to crack. For performance reasons usually only part of the kernel address is randomized, in open-source operating systems this randomization scheme is often known, and the kernel is always loaded fully into physical memory and doesn't get swapped out. While the location it is loaded to is also randomized, the kernel is mapped into the address space of all processes, so if you can find its address in any process you've also found it in every process. Haswell makes this even easier because all of the bits the Linux kernel randomizes are covered by the low 30 bits of the virtual address Haswell uses in the BTB index, which covers the entire kernel address range and means any kernel branch address can be determined exactly. The attacker finds branch instructions in the kernel code such as by disassembling it that service a particular system call and computes (this is feasible due to the smaller search space) all the possible locations that branch could be at, creates a "spy" function with a branch instruction positioned to try to force a BTB collision by computing to the same BTB index, executes the system call, and then executes the spy function. If the spy process (which times itself) determines its branch took longer than an average branch, it logs a hit, and the delta between ordinary execution and a BTB collision is unambiguously high (see Figure 7 in the paper). Now that you have the address of that code block branch, you can deduce the address of the entire kernel code block (because it's generally in the same page of memory due to the typical granularity of the randomization scheme), and try to get at it or abuse it. The entire process can take just milliseconds on a current CPU. The kernel is often specifically hardened against such attacks, however, and there are more tempting targets though they need more work. If you want to attack a user process (particularly one running as root, since that will have privileges you can subvert), you have to get your "spy" on the same virtual core as the victim process or otherwise they won't share a BTB -- in the case of the kernel, the system call always executes on the same virtual core via context switch, but that's not the case here. This requires manipulating the OS' process scheduler or running lots of spy processes, which slows the attack but is still feasible. Also, since you won't have a kernel system call to execute, you have to get the victim to do a particular task with a branch instruction, and that task needs to be something repeatable. Once this is done, however, the basic notion is the same. Even though only a limited number of ASLR bits can be recovered this way (remember that in Haswell's case, bit 30 and above are not used in the BTB, and full Linux ASLR uses bits 12 to 40, unlike the kernel), you can dramatically narrow the search space to the point where brute-force guessing may be possible. The whole process is certainly much more streamlined than earlier ASLR attacks which relied on fragile things like cache timing. As it happens, software mitigations can blunt or possibly even completely eradicate this exploit. Brute-force guessing addresses in the kernel usually leads to a crash, so anything that forces the attacker to guess the address of a victim routine in the kernel will likely cause the exploit to fail catastrophically. Get a couple of those random address bits outside the 30 bits Haswell uses in the BTB table index and bingo, a relatively simple fix. One could also make ASLR more granular to occur at the function, basic block or even single instruction level rather than merely randomizing the starting address of segments within the address space, though this is much more complicated. However, hardware is needed to close the gap completely. A proper hardware solution would be to either use most or all of the virtual address in the BTB to reduce the possibility of a collision, and/or to add a random salt to whatever indexing or hashing function is used for BTB entries that varies from process to process so a collision becomes less predictable. Either needs a change from Intel. This little fable should serve to remind us that monocultures are bad. This exploit in question is viable and potentially ugly but can be mitigated. That's not the point: the point is that the attack, particularly upon the kernel, is made more feasible by particular details of how Haswell chips handle branching. When everything gets funneled through the same design and engineering optics and ends up with the same implementation, if someone comes up with a simple, weapons-grade exploit for a flaw in that implementation that software can't mask, we're all hosed. This is another reason why we need an auditable, powerful alternative to x86/x86_64 on the desktop. And there's only one system in that class right now.Okay, okay, I'll stop banging you over the head with this stuff. I've got a couple more bugs under investigation that will be fixed in 45.5.0, and if you're having the issue where TenFourFox is not remembering your search engine of choice, please post your country and operating system here. [Less]
Posted 8 days ago by Air Mozilla
Weekly project updates from the Mozilla Connected Devices team.
Posted 8 days ago by Air Mozilla
This is a weekly call with some of the Reps to discuss all matters about/affecting Reps and invite Reps to share their work with everyone.
Posted 8 days ago by mkohler
Please join us in congratulating Mijanur Rahman Rayhan, Rep of the Month for September 2016! Mijanur is a Mozilla Rep and Tech Speaker from Sylhet, Bangladesh. With his diverse knowledge he organized hackathons around Connected Devices and held a ... [More] Web Compatibility event to find differences in different browsers.      Mijanur proved himself as a very active Mozillian through his different activities and work with different communities. With his patience and consistency to reach his goals he is always ready and prepared for these. He showed commitment to the Reps program and his proactive spirit these last elections by running as a nominee for the Cohort position in Reps Council. Be sure to follow his activities as he continues the activate series with a Rust workshop, Dive Into Rust events, Firefox Testpilot MozCoffees, Web Compatibility Sprint and Privacy and Security seminar with Bangladesh Police! Please join us in congratulating him on Discourse! [Less]
Posted 9 days ago by gerv
One of the big problems with IoT devices is default passwords – here’s the list coded into the malware that attacked Brian Krebs. But without a default password, you have to make each device unique and then give the randomly-generated password to the ... [More] user, perhaps by putting it on a sticky label. Again, my IoT vision post suggests a better solution. If the device’s public key and a password are in an RFID tag on it, and you just swipe that over your hub, the hub can find and connect securely to the device over SSL, and then authenticate itself to the device (using the password) as the user’s real hub, with zero configuration on the part of the user. And all of this works without the need for any UI or printed label which needs to be localized. Better usability, better security, better for the internet. [Less]
Posted 9 days ago by gerv
You know that problem where you want to label a coffee pot, but you just don’t have the right label? Technology to the rescue! Of course, new technology does come with some disadvantages compared to the old, as well as its many advantages: And ... [More] pinch-to-zoom on the picture viewer (because that’s what it uses) does mean you can play some slightly mean tricks on people looking for their caffeine fix: And how do you define what label the tablet displays? Easy: Seriously, can any reader give me one single advantage this system has over a paper label? [Less]
Posted 9 days ago by Laura
Filed under: Methods, Mozilla, Research
Posted 9 days ago by Daniel.Pocock
One of the projects proposed for this round of Outreachy is the PGP / PKI Clean Room live image. Interns, and anybody who decides to start using the project (it is already functional for command line users) need to decide about purchasing various ... [More] pieces of hardware, including a smart card, a smart card reader and a suitably secure computer to run the clean room image. It may also be desirable to purchase some additional accessories, such as a hardware random number generator. If you have any specific suggestions for hardware or can help arrange any donations of hardware for Outreachy interns, please come and join us in the pki-clean-room mailing list or consider adding ideas on the PGP / PKI clean room wiki. Choice of smart card For standard PGP use, the OpenPGP card provides a good choice. For X.509 use cases, such as VPN access, there are a range of choices. I recently obtained one of the SmartCard HSM cards, Card Contact were kind enough to provide me with a free sample. An interesting feature of this card is Elliptic Curve (ECC) support. More potential cards are listed on the OpenSC page here. Choice of card reader The technical factors to consider are most easily explained with a table: On disk Smartcard reader without PIN-pad Smartcard reader with PIN-pad Software Free/open Mostly free/open, Proprietary firmware in reader Key extraction Possible Not generally possible Passphrase compromise attack vectors Hardware or software keyloggers, phishing, user error (unsophisticated attackers) Exploiting firmware bugs over USB (only sophisticated attackers) Other factors No hardware Small, USB key form-factor Largest form factor Some are shortlisted on the GnuPG wiki and there has been recent discussion of that list on the GnuPG-users mailing list. Choice of computer to run the clean room environment There are a wide array of devices to choose from. Here are some principles that come to mind: Prefer devices without any built-in wireless communications interfaces, or where those interfaces can be removed Even better if there is no wired networking either Particularly concerned users may also want to avoid devices with opaque micro-code/firmware Small devices (laptops) that can be stored away easily in a locked cabinet or safe to prevent tampering No hard disks required Having built-in SD card readers or the ability to add them easily SD cards and SD card readers The SD cards are used to store the master private key, used to sign the certificates/keys on the smart cards. Multiple copies are kept. It is a good idea to use SD cards from different vendors, preferably not manufactured in the same batch, to minimize the risk that they all fail at the same time. For convenience, it would be desirable to use a multi-card reader: although the software experience will be much the same if lots of individual card readers or USB flash drives are used. Other devices One additional idea that comes to mind is a hardware random number generator (TRNG), such as the FST-01. Can you help with ideas or donations? If you have any specific suggestions for hardware or can help arrange any donations of hardware for Outreachy interns, please come and join us in the pki-clean-room mailing list or consider adding ideas on the PGP / PKI clean room wiki. [Less]
Posted 9 days ago by Tim Murray
We’ve spent the past two weeks asking people around the world to think about our four refined design directions for the Mozilla brand identity. The results are in and the data may surprise you. If you’re just joining this process, you can get ... [More] oriented here and here. Our objective is to refresh our Mozilla logo and related visual assets that support our mission and make it easier for people who don’t know us to get to know us. A reminder of the factors we’re taking into account in this phase. Data is our friend, but it is only one of several aspects to consider. In addition to the three quantitative surveys—of Mozillians, developers, and our target consumer audience—qualitative and strategic factors play an equal role. These include comments on this blog, constructive conversations with Mozillians, our 5-year strategic plan for Mozilla, and principles of good brand design. Here is what we showed, along with a motion study, for each direction:   We asked survey respondents to rate these design directions against seven brand attributes. Five of them—Innovative, Activist, Trustworthy, Inclusive/Welcoming, Opinionated—are qualities we’d like Mozilla to be known for in the future. The other two—Unique, Appealing—are qualities required for any new brand identity to be successful. Mozillians and developers meld minds. Members of our Mozilla community and the developers surveyed through MDN (the Mozilla Developer Network) overwhelmingly ranked Protocol 2.0 as the best match to our brand attributes. For over 700 developers and 450 Mozillians, Protocol scored highest across 6 of 7 measures. People with a solid understanding of Mozilla feel that a design embedded with the language of the internet reinforces our history and legacy as an Internet pioneer. The link’s role in connecting people to online know-how, opportunity and knowledge is worth preserving and fighting for. But consumers think differently. We surveyed people making up our target audience, 400 each in the U.S., U.K., Germany, France, India, Brazil, and Mexico. They are 18- to 34-year-old active citizens who make brand choices based on values, are more tech-savvy than average, and do first-hand research before making decisions (among other factors). We asked them first to rank order the brand attributes most important for a non-profit organization “focused on empowering people and building technology products to keep the internet healthy, open and accessible for everyone.” They selected Trustworthy and Welcoming as their top attributes. And then we also asked them to evaluate each of the four brand identity design systems against each of the seven brand attributes. For this audience, the design system that best fit these attributes was Burst. Why would this consumer audience choose Burst? Since this wasn’t a qualitative survey, we don’t know for sure, but we surmise that the colorful design, rounded forms, and suggestion of interconnectedness felt appropriate for an unfamiliar nonprofit. It looks like a logo. Also of note, Burst’s strategic narrative focused on what an open, healthy Internet feels and acts like, while the strategic narratives for the other design systems led with Mozilla’s role in world. This is a signal that our targeted consumer audience, while they might not be familiar with Mozilla, may share our vision of what the Internet could and should be. Why didn’t they rank Protocol more highly across the chosen attributes? We can make an educated guess that these consumers found it one dimensional by comparison, and they may have missed the meaning of the :// embedded in the wordmark. Although Dino 2.0 and Flame had their fans, neither of these design directions sufficiently communicated our desired brand attributes, as proven by the qualitative survey results as well as through conversations with Mozillians and others in the design community. By exploring them, we learned a lot about how to describe and show certain facets of what Mozilla offers to the world. But we will not be pursuing either direction. Where we go from here. Both Protocol and Burst have merits and challenges. Protocol is distinctly Mozilla, clearly about the Internet, and it reinforces our mission that the web stay healthy, accessible, and open. But as consumer testing confirmed, it lacks warmth, humor, and humanity. From a design perspective, the visual system surrounding it is too limited. By comparison, Burst feels fresh, modern, and colorful, and it has great potential in its 3D digital expression. As a result, it represents the Internet as a place of endless, exciting connections and possibilities, an idea reinforced by the strategic narrative. Remove the word “Mozilla,” though, and are there enough cues to suggest that it belongs to us? Our path forward is to take the strongest aspects of Burst—its greater warmth and dimensionality, its modern feel—and apply them to Protocol. Not to Frankenstein the two together, but to design a new, final direction that builds from both. We believe we can make Protocol more relatable to a non-technical audience, and build out the visual language surrounding it to make it both harder working and more multidimensional. Long live the link. What do we say to Protocol’s critics who have voiced concern that Mozilla is hitching itself to an Internet language in decline? We’re doubling down on our belief in the original intent of the Internet—that people should have the ability to explore, discover and connect in an unfiltered, unfettered, unbiased environment. Our mission is dedicated to keeping that possibility alive and well. For those who are familiar with the Protocol prompt, using the language of the Internet in our brand identity signals our resolve. For the unfamiliar, Protocol will offer an opportunity to start a conversation about who we are and what we believe. The language of the Internet will continue to be as important to building its future as it was in establishing its origin. We’ll have initial concepts for a new, dare-we-say final design within a few weeks. To move forward, first we’ll be taking a step back. We’ll explore different graphic styles, fonts, colors, motion, and surrounding elements, making use of the design network established by our agency partner johnson banks. In the meantime, tell us what you think. [Less]
Posted 9 days ago
The Rust team is happy to announce the latest version of Rust, 1.12.1. Rust is a systems programming language with a focus on reliability, performance, and concurrency. As always, you can install Rust 1.12.1 from the appropriate page on our website ... [More] , or install via rustup with rustup update stable. What’s in 1.12.1 stable Wait… one-point-twelve-point… one? In the release announcement for 1.12 a few weeks ago, we said: The release of 1.12 might be one of the most significant Rust releases since 1.0. It was true. One of the biggest changes was turning on a large compiler refactoring, MIR, which re-architects the internals of the compiler. The overall process went like this: Initial MIR support landed in nightlies back in Rust 1.6. While work was being done, a flag, --enable-orbit, was added so that people working on the compiler could try it out. Back in October, we would always attempt to build MIR, even though it was not being used. A flag was added, -Z orbit, to allow users on nightly to try and use MIR rather than the traditional compilation step (‘trans’). After substantial testing over months and months, for Rust 1.12, we enabled MIR by default. In Rust 1.13, MIR will be the only option. A change of this magnitude is huge, and important. So it’s also important to do it right, and do it carefully. This is why this process took so long; we regularly tested the compiler against every crate on crates.io, we asked people to try out -Z orbit on their private code, and after six weeks of beta, no significant problems appeared. So we made the decision to keep it on by default in 1.12. But large changes still have an element of risk, even though we tried to reduce that risk as much as possible. And so, after release, 1.12 saw a fair number of regressions that we hadn’t detected in our testing. Not all of them are directly MIR related, but when you change the compiler internals so much, it’s bound to ripple outward through everything. Why make a point release? Now, given that we have a six-week release cycle, and we’re halfway towards Rust 1.13, you may wonder why we’re choosing to cut a patch version of Rust 1.12 rather than telling users to just wait for the next release. We have previously said something like “point releases should only happen in extreme situations, such as a security vulnerability in the standard library.” The Rust team cares deeply about the stability of Rust, and about our users’ experience with it. We could have told you all to wait, but we want you to know how seriously we take this stuff. We think it’s worth it to demonstrate our commitment to you by putting in the work of making a point release in this situation. Furthermore, given that this is not security related, it’s a good time to practice actually cutting a point release. We’ve never done it before, and the release process is semi-automated but still not completely so. Having a point release in the world will also shake out any bugs in dealing with point releases in other tooling as well, like rustup. Making sure that this all goes smoothly and getting some practice going through the motions will be useful if we ever need to cut some sort of emergency point release due to a security advisory or anything else. This is the first Rust point release since Rust 0.3.1, all the way back in 2012, and marks 72 weeks since Rust 1.0, when we established our six week release cadence along with a commitment to aggressive stability guarantees. While we’re disappointed that 1.12 had these regressions, we’re really proud of Rust’s stability and will to continue expanding our efforts to ensure that it’s a platform you can rely on. We want Rust to be the most reliable programming platform in the world. A note about testing on beta One thing that you, as a user of Rust, can do to help us fix these issues sooner: test your code against the beta channel! Every beta release is a release candidate for the next stable release, so for the cost of an extra build in CI, you can help us know if there’s going to be some sort of problem before it hits a stable release! It’s really easy. For example, on Travis, you can use this as your .travis.yml: language: rust rust: - stable - beta And you’ll test against both. Furthermore, if you’d like to make it so that any beta failure doesn’t fail your own build, do this: matrix: allow_failures: - rust: beta The beta build may go red, but your build will stay green. Most other CI systems, such as AppVeyor, should support something similar. Check the documentation for your specific continuous integration product for full details. Full details There were nine issues fixed in 1.12.1, and all of those fixes have been backported to 1.13 beta as well. ICE: ‘rustc’ panicked at ‘assertion failed: concrete_substs.is_normalized_for_trans()’ #36381 Confusion with double negation and booleans rustc 1.12.0 fails with SIGSEGV in release mode (syn crate 0.8.0) Rustc 1.12.0 Windows build of ethcore crate fails with LLVM error 1.12.0: High memory usage when linking in release mode with debug info Corrupted memory after updated to 1.12 “Let NullaryConstructor = something;” causes internal compiler error: “tried to overwrite interned AdtDef” Fix ICE: inject bitcast if types mismatch for invokes/calls/stores debuginfo: Handle spread_arg case in MIR-trans in a more stable way. In addition, there were four more regressions that we decided not to include in 1.12.1 for various reasons, but we’ll be working on fixing those as soon as possible as well. ICE, possibly related to associated types of associated types? Compilation of a crate using a large static map fails on latest i686-pc-windows-gnu Beta Regression: “no method found” error when calling same method twice, with HRTB impl ICE: fictitious type sizing_type_of You can see the full diff from 1.12.0 to 1.12.1 here. [Less]