5 ms·

To Google Chrome's spellchecker. It's a bad vulnerability, but it's unlikely that it's really the attack vector here.

ceejayoz 8y ago
Yeah. This is pretty far-fetched. > He argues that Coinomi’s built-in spell checker automatically checked his seed phrase which involved sending it as plain text to a Google-owned website. This meant it could have been intercepted, leading to the loss of funds. "As plain text" here almost certainly means "fully encrypted with TLS"...
- cabaalis 8y ago
  I felt like you did, and watched the video and he is certainly looking at an HTTPS data stream. I think the argument though is that the request is being logged and that some employee is reviewing logs and grabbing data. If that is the case, then it seems there is a known pool of suspects to charge with theft...
  - ceejayoz 8y ago
    Yeah, and the amount of data to sift through there would be truly enormous. I'd wager there was just some malware on the machine.
    - SketchySeaBeast 8y ago
      Apparently it's a list of 12 words from 2048. I guess you could potentially try and pattern match that, but that'd be a ton of a sifting.
    - Phlarp 8y ago
      The amount of data to sift through? What website am I on right now? Just grep for 64 character strings. The regex is so simple I think it a little naive not to assume _someone_ has a script running to sniff out keys. It would be trivial for an ISP employee to watch for such strings in unencrypted traffic streams. Think what cloudflare could find if they went looking.
      - ceejayoz 8y ago
        The stream isn't unencrypted, though. Chrome's cloud spellchecker sends over HTTPS, for obvious reasons. (It's also an opt-in feature.) I strongly suspect grepping against inbound production traffic to Google's spellcheck service is fairly difficult to do unnoticed. Malware, on the other hand, is quite prevalent. Plenty of folks lose their crypto on a daily basis in that manner.
        Phlarp 8y ago
        Sure, but think of how porous this could be even with HTTPS-- it doesn't have to be a google admin grepping inbound traffic. It could be happening with a custom installed certificate for a workplace or university network or it could be happening with a third party service or API behind HTTPS termination. Even something trivial like analytics could potentially leak this info. Malware is certainly a possibility, but it could just as easily have been phished or grabbed with an XSS.
  - tbodt 8y ago
    Access to this data is very tightly controlled, it's likely a single digit number of people.
Veen 8y ago
Right. The "thief" would have to be extremely lucky to have been intercepting the right data, recognized what the key was, and used it. As mentioned in the story, I suspect this chap found the vulnerability and is hoping to parlay it into a payout.
- cjbprime 8y ago
  No, more than that: assuming the connection to the spell checker uses TLS, the thief would have to be Google. I'd be surprised if it doesn't use TLS?
  - jakevoytko 8y ago
    The thief in that case would likely be a browser extension
    - cjbprime 8y ago
      It's a desktop app.
  - hackinthebochs 8y ago
    There was another instance of a massive coin theft a year or so ago and the weak link again was the recovery seed being sent to a Google server. The guy described his operational security and it seemed like he did everything right. The only slip up he could point to was that he had mistakenly pasted his seed into his Chrome address bar (which then performs an automatic lookup). It was shortly after that when his funds were drained. I'm certainly not saying it was someone at Google, but it would be a mistake to not consider them an adversary in the battle to secure your funds.
    - 781 8y ago
      A ton of people use GMail for their crypto accounts. Claiming that someone at Google stole the funds is quite an extraordinary claim. You should have more proof than just the seed being sent to their spellchecker.
sofaofthedamned 8y ago
Exactly. There's billions of entries there each day, it's just symptomatic of bad secops where the spellchecker upload is the canary for other rank stupidity.
tzumby 8y ago
Why in the world would they need a spell checker when the whole mnemonic phrase standard has a checksum (last word in every phrase is the checksum)
- wcoenen 8y ago
  The Android EditText control has this enabled by default, and the documentation of the control doesn't mention it: https://developer.android.com/reference/android/widget/EditText https://developer.android.com/reference/android/widget/EditT... To disable it, the developer needs to add the "textNoSuggestions" flag to the input type.
GuB-42 8y ago
Official response by Coinomi https://medium.com/coinomi/official-statement-on-spell-check-findings-547ca348676b https://medium.com/coinomi/official-statement-on-spell-check... Summary: Yes, there was a bug, we fixed it, but it was not exploitable in practice for a variety of reasons. Most importantly, the seed phrase wasn’t being transmitted in plain text.

Yeah. This is pretty far-fetched. > He argues that Coinomi’s built-in spell checker automatically checked his seed phrase which involved sending it as plain text to a Google-owned website. This meant it could have been intercepted, leading to the loss of funds. "As plain text" here almost certainly means "fully encrypted with TLS"...

cabaalis 8y ago
I felt like you did, and watched the video and he is certainly looking at an HTTPS data stream. I think the argument though is that the request is being logged and that some employee is reviewing logs and grabbing data. If that is the case, then it seems there is a known pool of suspects to charge with theft...
- ceejayoz 8y ago
  Yeah, and the amount of data to sift through there would be truly enormous. I'd wager there was just some malware on the machine.
  - SketchySeaBeast 8y ago
    Apparently it's a list of 12 words from 2048. I guess you could potentially try and pattern match that, but that'd be a ton of a sifting.
  - Phlarp 8y ago
    The amount of data to sift through? What website am I on right now? Just grep for 64 character strings. The regex is so simple I think it a little naive not to assume _someone_ has a script running to sniff out keys. It would be trivial for an ISP employee to watch for such strings in unencrypted traffic streams. Think what cloudflare could find if they went looking.
    - ceejayoz 8y ago
      The stream isn't unencrypted, though. Chrome's cloud spellchecker sends over HTTPS, for obvious reasons. (It's also an opt-in feature.) I strongly suspect grepping against inbound production traffic to Google's spellcheck service is fairly difficult to do unnoticed. Malware, on the other hand, is quite prevalent. Plenty of folks lose their crypto on a daily basis in that manner.
      - Phlarp 8y ago
        Sure, but think of how porous this could be even with HTTPS-- it doesn't have to be a google admin grepping inbound traffic. It could be happening with a custom installed certificate for a workplace or university network or it could be happening with a third party service or API behind HTTPS termination. Even something trivial like analytics could potentially leak this info. Malware is certainly a possibility, but it could just as easily have been phished or grabbed with an XSS.
- tbodt 8y ago
  Access to this data is very tightly controlled, it's likely a single digit number of people.

Veen 8y ago

Right. The "thief" would have to be extremely lucky to have been intercepting the right data, recognized what the key was, and used it. As mentioned in the story, I suspect this chap found the vulnerability and is hoping to parlay it into a payout.

cjbprime 8y ago
No, more than that: assuming the connection to the spell checker uses TLS, the thief would have to be Google. I'd be surprised if it doesn't use TLS?
- jakevoytko 8y ago
  The thief in that case would likely be a browser extension
  - cjbprime 8y ago
    It's a desktop app.
- hackinthebochs 8y ago
  There was another instance of a massive coin theft a year or so ago and the weak link again was the recovery seed being sent to a Google server. The guy described his operational security and it seemed like he did everything right. The only slip up he could point to was that he had mistakenly pasted his seed into his Chrome address bar (which then performs an automatic lookup). It was shortly after that when his funds were drained. I'm certainly not saying it was someone at Google, but it would be a mistake to not consider them an adversary in the battle to secure your funds.
  - 781 8y ago
    A ton of people use GMail for their crypto accounts. Claiming that someone at Google stole the funds is quite an extraordinary claim. You should have more proof than just the seed being sent to their spellchecker.

sofaofthedamned 8y ago

Exactly. There's billions of entries there each day, it's just symptomatic of bad secops where the spellchecker upload is the canary for other rank stupidity.

tzumby 8y ago

Why in the world would they need a spell checker when the whole mnemonic phrase standard has a checksum (last word in every phrase is the checksum)

wcoenen 8y ago
The Android EditText control has this enabled by default, and the documentation of the control doesn't mention it: https://developer.android.com/reference/android/widget/EditText https://developer.android.com/reference/android/widget/EditT... To disable it, the developer needs to add the "textNoSuggestions" flag to the input type.

GuB-42 8y ago

Official response by Coinomi https://medium.com/coinomi/official-statement-on-spell-check-findings-547ca348676b https://medium.com/coinomi/official-statement-on-spell-check... Summary: Yes, there was a bug, we fixed it, but it was not exploitable in practice for a variety of reasons. Most importantly, the seed phrase wasn’t being transmitted in plain text.