Yahoo! crypto! queen! turns! security! code! into! evil! tracker!

HTTP Strict Transport Security isn't working as advertised or planned


Yahoo! crypto ace Yan Zhu has found twin attacks that allow websites to learn the web histories of visitors users by targeting HTTP Strict Transport Security (HSTS).

The timing attack, which works regardless of cookie clearing, was demonstrated on Firefox and Chrome last Sunday at the Toorcon security conference.

The attack allows malicious admins to track only the HSTS domains and subdomains rather than full URLs a user has visited which restricts the threat since most sites including major web operators have yet to adopt the lauded security measure.

It also does not work against Safari, Internet Explorer, or Chrome users on Apple devices.

Zhu also detailed how a website can abuse the certificate pinning browser security measure by serving a supercookie to users that can be later read by that site to determine visitor browser histories.

The hacker (@bcrypt) says the work is "unusual" for an author of privacy tools.

"These features are really hard to turn off," Zhu told the conference, adding that it could be further developed to reveal full user URL paths.

"If you are sneaky.com and you want to fingerprint users and you know that some other site is going to support HSTS … you can know wether a user has visited it and gotten the HSTS pin.

"A bad certificate chain will cause the browser reporting to fire a validation report which includes …. a supercookie."

The flaws have been reported to Google and Mozilla.

Zhu, who works on a series of cryptographic initiatives and with the Electronic Frontier Foundation created a proof-of-concept site to showcase the exploit, since dubbed "Sniffly".

Among the sites that can be determined includes the infamous Kick Ass Torrents piracy site, Reddit, and Kickstarter.

Users running the HTTPS Everywhere extension or an advertising blocker are a little safer since it throws false positives into the list of sites a user is supposed to have visited but those can be identified with up to 80 percent accuracy

Firefox security bods are said to be evaluating the attacks and brewing means to defeat it.

Zhu, who has asked us to refer to her as a "crypto witch", describes how Sniffly works on her blog:

A user's browser attempts to load images from various HSTS domains over HTTP which are harvested from a scrape of HSTS domains in the Alexa top one million.

Sniffly sets a content security policy (CSP) that restricts images to HTTP, so image sources are blocked before they are redirected to HTTPS. This is crucial, because if the browser completes a request to the HTTPS site, then it will receive the HSTS pin, and the attack will no longer work when the user visits Sniffly.

When an image gets blocked by CSP, its onerror handler is called. In this case, theonerror handler does some fancy tricks to semi-reliably time how long it took for the image to be redirected from HTTP to HTTPS. If this time is on the order of a millisecond, it was an HSTS redirect (no network request was made), which means the user has visited the image’s domain before. If it’s on the order of 100 milliseconds, then a network request probably occurred, meaning that the user hasn’t visited the image’s domain.

Zhu's slides are also available here (PDF). ®

Similar topics


Other stories you might like

  • NASA's InSight doomed as Mars dust coats solar panels
    The little lander that couldn't (any longer)

    The Martian InSight lander will no longer be able to function within months as dust continues to pile up on its solar panels, starving it of energy, NASA reported on Tuesday.

    Launched from Earth in 2018, the six-metre-wide machine's mission was sent to study the Red Planet below its surface. InSight is armed with a range of instruments, including a robotic arm, seismometer, and a soil temperature sensor. Astronomers figured the data would help them understand how the rocky cores of planets in the Solar System formed and evolved over time.

    "InSight has transformed our understanding of the interiors of rocky planets and set the stage for future missions," Lori Glaze, director of NASA's Planetary Science Division, said in a statement. "We can apply what we've learned about Mars' inner structure to Earth, the Moon, Venus, and even rocky planets in other solar systems."

    Continue reading
  • The ‘substantial contributions’ Intel has promised to boost RISC-V adoption
    With the benefit of maybe revitalizing the x86 giant’s foundry business

    Analysis Here's something that would have seemed outlandish only a few years ago: to help fuel Intel's future growth, the x86 giant has vowed to do what it can to make the open-source RISC-V ISA worthy of widespread adoption.

    In a presentation, an Intel representative shared some details of how the chipmaker plans to contribute to RISC-V as part of its bet that the instruction set architecture will fuel growth for its revitalized contract chip manufacturing business.

    While Intel invested in RISC-V chip designer SiFive in 2018, the semiconductor titan's intentions with RISC-V evolved last year when it revealed that the contract manufacturing business key to its comeback, Intel Foundry Services, would be willing to make chips compatible with x86, Arm, and RISC-V ISAs. The chipmaker then announced in February it joined RISC-V International, the ISA's governing body, and launched a $1 billion innovation fund that will support chip designers, including those making RISC-V components.

    Continue reading
  • FBI warns of North Korean cyberspies posing as foreign IT workers
    Looking for tech talent? Kim Jong-un's friendly freelancers, at your service

    Pay close attention to that resume before offering that work contract.

    The FBI, in a joint advisory with the US government Departments of State and Treasury, has warned that North Korea's cyberspies are posing as non-North-Korean IT workers to bag Western jobs to advance Kim Jong-un's nefarious pursuits.

    In guidance [PDF] issued this week, the Feds warned that these techies often use fake IDs and other documents to pose as non-North-Korean nationals to gain freelance employment in North America, Europe, and east Asia. Additionally, North Korean IT workers may accept foreign contracts and then outsource those projects to non-North-Korean folks.

    Continue reading
  • Google opens the pod doors on Bay View campus
    A futuristic design won't make people want to come back – just ask Apple

    After nearly a decade of planning and five years of construction, Google is cutting the ribbon on its Bay View campus, the first that Google itself designed.

    The Bay View campus in Mountain View – slated to open this week – consists of two office buildings (one of which, Charleston East, is still under construction), 20 acres of open space, a 1,000-person event center and 240 short-term accommodations for Google employees. The search giant said the buildings at Bay View total 1.1 million square feet. For reference, that's less than half the size of Apple's spaceship. 

    The roofs on the two main buildings, which look like pavilions roofed in sails, were designed that way for a purpose: They're a network of 90,000 scale-like solar panels nicknamed "dragonscales" for their layout and shimmer. By scaling the tiles, Google said the design minimises damage from wind, rain and snow, and the sloped pavilion-like roof improves solar capture by adding additional curves in the roof. 

    Continue reading
  • Pentester pops open Tesla Model 3 using low-cost Bluetooth module
    Anything that uses proximity-based BLE is vulnerable, claim researchers

    Tesla Model 3 and Y owners, beware: the passive entry feature on your vehicle could potentially be hoodwinked by a relay attack, leading to the theft of the flash motor.

    Discovered and demonstrated by researchers at NCC Group, the technique involves relaying the Bluetooth Low Energy (BLE) signals from a smartphone that has been paired with a Tesla back to the vehicle. Far from simply unlocking the door, this hack lets a miscreant start the car and drive away, too.

    Essentially, what happens is this: the paired smartphone should be physically close by the Tesla to unlock it. NCC's technique involves one gadget near the paired phone, and another gadget near the car. The phone-side gadget relays signals from the phone to the car-side gadget, which forwards them to the vehicle to unlock and start it. This shouldn't normally happen because the phone and car are so far apart. The car has a defense mechanism – based on measuring transmission latency to detect that a paired device is too far away – that ideally prevents relayed signals from working, though this can be defeated by simply cutting the latency of the relay process.

    Continue reading
  • Google assuring open-source code to secure software supply chains
    Java and Python packages are the first on the list

    Google has a plan — and a new product plus a partnership with developer-focused security shop Snyk — that attempts to make it easier for enterprises to secure their open source software dependencies.

    The new service, announced today at the Google Cloud Security Summit, is called Assured Open Source Software. We're told it will initially focus on some Java and Python packages that Google's own developers prioritize in their workflows. 

    These two programming languages have "particularly high-risk profiles," Google Cloud Cloud VP and GM Sunil Potti said in response to The Register's questions. "Remember Log4j?" Yes, quite vividly.

    Continue reading
  • Rocket Lab is taking NASA's CAPSTONE to the Moon
    Mission to lunar orbit is further than any Photon satellite bus has gone before

    Rocket Lab has taken delivery of NASA's CAPSTONE spacecraft at its New Zealand launch pad ahead of a mission to the Moon.

    It's been quite a journey for CAPSTONE [Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment], which was originally supposed to launch from Rocket Lab's US launchpad at Wallops Island in Virginia.

    The pad, Launch Complex 2, has been completed for a while now. However, delays in certifying Rocket Lab's Autonomous Flight Termination System (AFTS) pushed the move to Launch Complex 1 in Mahia, New Zealand.

    Continue reading
  • Alibaba Cloud adds third datacenter in Germany
    More Euro-presence than any other Chinese company, but still nowhere near Google or AWS

    Alibaba has pulled ahead of its Chinese rivals in Europe with the opening of a third datacenter in Germany.

    The company said the Frankfurt datacenter serves cloud computing products to Europe and "adheres to the highest security standards and the strict compliance regulations set out in the Cloud Computing Compliance Controls Catalog (C5) in Germany."

    The addition brings Alibaba Cloud to a network of 84 availability zones in 27 regions worldwide. The company's first European cloud center arrived in Frankfurt in 2016.

    Continue reading

Biting the hand that feeds IT © 1998–2022