Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Major new iOS bug can crash iPhones and disable access to apps and iMessages

theverge.com

Post reply on HN
Print view View original

31–40 of 122 posts

Re: Major new iOS bug can crash iPhones and disable access to apps and iMessages

#31

Post by saosebastiao »

evfanknitram wrote: post #9
taylodl wrote: post #2

What Apple, and Microsoft before them, are discovering is the tools and processes we use to create software simply doesn't scale. We're simply reaching the limits of what these giant software teams are able to produce and keep running. We can discuss solutions, but currently not everybody even agrees we have a problem. That's the first step we need to take.

Waiting for everyone to agree seems like a very futile and inefficient way to achieve progress.

That's true, but critical mass is more important than consensus and we're not close to that either.

Re: Major new iOS bug can crash iPhones and disable access to apps and iMessages

#33

Post by arenaninja »

RandallBrown wrote: post #16
Cknight70 wrote: post #15

Here's a link to the character if someone wants to test it themselves https://pastebin.com/9Tr8ytTr

Wow, that even crashes Safari on my Mac.

Not crashing mine, using OSX 10.13.3, Safari 11.0.3

Re: Major new iOS bug can crash iPhones and disable access to apps and iMessages

#34

Post by torstenvl »

Cknight70 wrote: post #15

Here's a link to the character if someone wants to test it themselves https://pastebin.com/9Tr8ytTr

Doesn't crash iOS 10.3 (although it doesn't seem to render correctly either)

https://imgur.com/cglhVS5

Would be really nice if Apple would stop treating its beta software as a final release.

Re: Major new iOS bug can crash iPhones and disable access to apps and iMessages

#35

Post by kens »

What's the Unicode codepoint of the character? Is it a single Unicode codepoint or multiple? (I tried to search for info on the web, but Chrome kept crashing.)

Supposedly it's a normal Telugu character, but how could that have gotten past even minimal testing in Hyderabad? Or is it some strange combining corner case? Telugu script is kind of unusual in Unicode, since it is syllabic but has separate codepoints for vowels and consonants, so character rendering is done by combining a vowel and consonant character into a totally different character. (Apologies for probably oversimplifying and mangling that explanation.) This is unlike Japanese katakana and hiragana, which have separate Unicode code points for each syllable so rendering is straightforward.

https://en.wikipedia.org/wiki/Telugu_script

Re: Major new iOS bug can crash iPhones and disable access to apps and iMessages

#37

Post by rspeer »

xoa wrote: post #11
hello_asdf wrote: post #3

I've never done any fuzzing personally, but wouldn't this be discoverable internally during testing? I would think that they would attempt sending all possible characters, especially because they've had issues with this in the past.

> I've never done any fuzzing personally, but wouldn't this be discoverable internally during testing? Yes. This seems like a somewhat embarrassing fail in terms of whatever automated testing Apple does. It's a pretty minimal and restricted case of fuzzing, in fact I'm not sure it'd qualify as "fuzzing" at all because here the crasher is just an actual Unicode character, part of a fixed set that can be completely run…

I wouldn't be so quick to call Unicode characters a "fixed set", because of the way that they can be arbitrarily composed from multiple codepoints. If you've encountered zalgo-text, for example, you've encountered characters made from a base letter and like 20 combining codepoints. Enumerating all of the possible characters is infeasible.

To be specific, here are the codepoints in the character from Pastebin:

    U+0C1C  [Lo] TELUGU LETTER JA
    U+0C4D  [Mn] TELUGU SIGN VIRAMA
    U+0C1E  [Lo] TELUGU LETTER NYA
    U+200C  [Cf] ZERO WIDTH NON-JOINER
    U+0C3E  [Mn] TELUGU VOWEL SIGN AA
I don't know if the ZWNJ is in there to make the bug happen or to neutralize it. But the entire group of five codepoints renders and selects as one character for me (in Chrome on Ubuntu).

Re: Major new iOS bug can crash iPhones and disable access to apps and iMessages

#38

Post by virgilp »

TazeTSchnitzel wrote: post #26
bla2 wrote: post #21

Earlier quoted context omitted.

More like "this is why we should use LLVM's libFuzzer or similar". Apple is just not doing basic code hygiene stuff here.

Fuzzing finds bugs, using a safe language precludes them.

No it doesn't. At best it precludes a certain class of bugs (which may be very significant, but it's not a silver bullet)

Re: Major new iOS bug can crash iPhones and disable access to apps and iMessages

#39

Post by esnard »

kens wrote: post #35

What's the Unicode codepoint of the character? Is it a single Unicode codepoint or multiple? (I tried to search for info on the web, but Chrome kept crashing.) Supposedly it's a normal Telugu character, but how could that have gotten past even minimal testing in Hyderabad? Or is it some strange combining corner case? Telugu script is kind of unusual in Unicode, since it is syllabic but has separate codepoints for vow…

Multiple codepoints.

U+0C1C U+0C4D U+0C1E U+200C U+0C3E

Re: Major new iOS bug can crash iPhones and disable access to apps and iMessages

#40

Post by [deleted] »

kens wrote: post #35

What's the Unicode codepoint of the character? Is it a single Unicode codepoint or multiple? (I tried to search for info on the web, but Chrome kept crashing.) Supposedly it's a normal Telugu character, but how could that have gotten past even minimal testing in Hyderabad? Or is it some strange combining corner case? Telugu script is kind of unusual in Unicode, since it is syllabic but has separate codepoints for vow…

[deleted]
Post reply on HN