3 ms·

I'd hope for most things on my iphone or newish name brand android, but I don't have the audits to prove it for everything. There were some amazing phishing at

I'd hope for most things on my iphone or newish name brand android, but I don't have the audits to prove it for everything. There were some amazing phishing attacks way back when the iPhone could do a single click jailbreak through the web. While that scene publicly is mostly dead for people that want a Cydia app, there's definitely a big money private game that still exists. I don't think it's a totally safe assumption to just trust that a sophisticated man in the middle at a dense event isn't possible. Unlikely, sure... Maybe I'm not even the best target. My 75 year old uncle with his thrift store Android might be in a common set of outdated devices ripe for picking, and wouldn't be able to catch a phish if it slapped him. Let alone something that didn't need user input. That's a pretty reasonable inroad to all sorts of stuff if your patient and inclined. I dunno, I think it's a reasonable thing to at least ponder in our current world of ubiquitous barely updated pocket linux slabs.

geofft 8y ago
Jailbreaks through the web are always a threat - they don't stop being a threat because you're using a legit cell tower. So I think that "what if there's a low-interaction 0-day" doesn't really interact with Stingrays. If you're worried about it, avoiding events where Stingrays are likely to be used doesn't really help you. iOS does verify OS software via a secure-boot-style chain of trust, starting with a public key that's part of ROM, and there's rollback prevention for the OS, the baseband, and the Secure Enclave's software. https://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/business/docs/iOS_Security_Guide.pdf (At least, if you believe Apple, and if you don't, stop putting interesting info on your Apple cell phone.) Android also does verified boot https://source.android.com/security/verifiedboot/verified-boot https://source.android.com/security/verifiedboot/verified-bo... but device support is probably all over the place. I think that anything running Android 6 or later is required to use ARM TrustZone, but it's probably a lot easier to defeat than iOS's mechanism. Rupprecht et al. 2016 find that most devices on the market at the time - including the iPhone 5S and 6S and the Nexus 5 and 7 - would accept the LTE no-encryption mode ("EEA0") without showing any UI warning or indicator; see section 5 / table 2 in https://www.usenix.org/system/files/conference/woot16/woot16-paper-rupprecht.pdf https://www.usenix.org/system/files/conference/woot16/woot16... . They also find that some Huawei chipsets will accept the LTE no-integrity-protection mode ("EIA0"), although most devices reject that. I haven't seen a newer version of this research. NIST points out (https://csrc.nist.gov/CSRC/media/Presentations/LTE-Security-How-Good-is-it/images-media/day2_research_200-250.pdf https://csrc.nist.gov/CSRC/media/Presentations/LTE-Security-... slides 40 and 47 - warning, 3-megabyte PDF) that most phones support downgrading to older standards - which is what you want for roaming, but if you're in a densely populated area with a clear view of the sky and your phone shows "3G", maybe you should be suspicious. Your 75-year-old uncle with a thrift store Android is almost certainly at serious risk, yes, but I think his primary problem is that this Android isn't getting updates any more and there are just publicly known exploits that anyone can use. Personally, I'd say the best thing is to get him a ~$150 iPhone SE from one of the prepaid carriers, because that's what they're going for these days, the SE should have about two more years of security support lifecycle left, and it does have a Secure Enclave.
- stuntkite 8y ago
  Thank you for your thoughtful breakdown and useful links!

geofft 8y ago

Jailbreaks through the web are always a threat - they don't stop being a threat because you're using a legit cell tower. So I think that "what if there's a low-interaction 0-day" doesn't really interact with Stingrays. If you're worried about it, avoiding events where Stingrays are likely to be used doesn't really help you. iOS does verify OS software via a secure-boot-style chain of trust, starting with a public key that's part of ROM, and there's rollback prevention for the OS, the baseband, and the Secure Enclave's software. https://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/business/docs/iOS_Security_Guide.pdf (At least, if you believe Apple, and if you don't, stop putting interesting info on your Apple cell phone.) Android also does verified boot https://source.android.com/security/verifiedboot/verified-boot https://source.android.com/security/verifiedboot/verified-bo... but device support is probably all over the place. I think that anything running Android 6 or later is required to use ARM TrustZone, but it's probably a lot easier to defeat than iOS's mechanism. Rupprecht et al. 2016 find that most devices on the market at the time - including the iPhone 5S and 6S and the Nexus 5 and 7 - would accept the LTE no-encryption mode ("EEA0") without showing any UI warning or indicator; see section 5 / table 2 in https://www.usenix.org/system/files/conference/woot16/woot16-paper-rupprecht.pdf https://www.usenix.org/system/files/conference/woot16/woot16... . They also find that some Huawei chipsets will accept the LTE no-integrity-protection mode ("EIA0"), although most devices reject that. I haven't seen a newer version of this research. NIST points out (https://csrc.nist.gov/CSRC/media/Presentations/LTE-Security-How-Good-is-it/images-media/day2_research_200-250.pdf https://csrc.nist.gov/CSRC/media/Presentations/LTE-Security-... slides 40 and 47 - warning, 3-megabyte PDF) that most phones support downgrading to older standards - which is what you want for roaming, but if you're in a densely populated area with a clear view of the sky and your phone shows "3G", maybe you should be suspicious. Your 75-year-old uncle with a thrift store Android is almost certainly at serious risk, yes, but I think his primary problem is that this Android isn't getting updates any more and there are just publicly known exploits that anyone can use. Personally, I'd say the best thing is to get him a ~$150 iPhone SE from one of the prepaid carriers, because that's what they're going for these days, the SE should have about two more years of security support lifecycle left, and it does have a Secure Enclave.

stuntkite 8y ago
Thank you for your thoughtful breakdown and useful links!