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A persistent denial of service vulnerability affecting iOS

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Re: A persistent denial of service vulnerability affecting iOS

#21

Post by userbinator »

sodality2 wrote: post #18
userbinator wrote: post #10

Earlier quoted context omitted.

Perhaps the limit was "available memory"? It's not hard to imagine how a programmer who has only ever worked with dynamic languages and basically doesn't know what a fixed-length-buffer is could be completely oblivious to it. Then again, what is an appropriate limit on the length of the name of a HomeKit device? I'm tempted to say 255, but I'm sure someone else would disagree. I've been in design meetings where such…

I can't imagine anyone would disagree with 1024 characters.

"But that doesn't fit in a byte; why not make it 64k instead so it's 2 bytes?"

"Why not 1023?"

"Even 1023 is too long, I don't think anyone would need that."

"What if ?"

"How about 32?"

Having been in a few meetings that went in that direction, I am not surprised that they couldn't agree on a limit. "Design by committee" at its worst.

Re: A persistent denial of service vulnerability affecting iOS

#22

Post by tshaddox »

sebastien_b wrote: post #13
pxeboot wrote: post #12

Earlier quoted context omitted.

> Which makes the whole point of backups of the device totally pointless. Isn't this exactly how backups should work? Do you really want Apple deciding which settings/data are not important to you?

The backups aren't the problem - what is the problem is Apple's "solution" to a clear bug being "don't restore from backups" (for the cellular-data draining bug). Instead of asking you to lose all your data as a workaround to a bad bug, they should actually fix that bug properly, so that it's no longer a bug. Likely the same with the bug described in this story - if someone ends up affected by it, they're basically p…

I don’t see any indication that Apple recommends this workaround.

Re: A persistent denial of service vulnerability affecting iOS

#23

Post by wang_li »

dv_dt wrote: post #14
pxeboot wrote: post #12

Earlier quoted context omitted.

> Which makes the whole point of backups of the device totally pointless. Isn't this exactly how backups should work? Do you really want Apple deciding which settings/data are not important to you?

No but it would be nice to be able to selectively restore a subset of backups.

Backups should be able to be merged with data on the phone. The use case is I want to travel overseas but I don't want various border control entities to make copies of my phone contents, so I back it up and reset the phone to factory defaults. Then I go on my trip and take pictures and receive texts and etc. When I get home I should be able to merge the pre-trip backup and the during trip stuff into a single set of contents on my phone.

Re: A persistent denial of service vulnerability affecting iOS

#24

Post by sebastien_b »

tshaddox wrote: post #22
sebastien_b wrote: post #13

Earlier quoted context omitted.

The backups aren't the problem - what is the problem is Apple's "solution" to a clear bug being "don't restore from backups" (for the cellular-data draining bug). Instead of asking you to lose all your data as a workaround to a bad bug, they should actually fix that bug properly, so that it's no longer a bug. Likely the same with the bug described in this story - if someone ends up affected by it, they're basically p…

I don’t see any indication that Apple recommends this workaround.

I was told this by Apple when I brought up the problem through their “support” for the cellular drain issue.

Re: A persistent denial of service vulnerability affecting iOS

#25

Post by rootsudo »

Lammy wrote: post #8
masklinn wrote: post #5

Uh. I wonder if this can still be triggered when the Home application has been removed from the device? I expect so as IIRC builtin-in application removal is really just hiding them and all the functions are part of priviledged bundles shipped with the OS.

> all the functions are part of privileged bundles shipped with the OS Luckily a lot of these can be disabled when jailbroken: https://i.imgur.com/KhGmGrf.png

What app is that?

I tried to get into cydia and such as of late, and it's a confusing ecosystem, you need to find specific marketplace links from github to browse and then alot of stuff is very legacy and not organized.

Would love to jb but it is complicated.

Re: A persistent denial of service vulnerability affecting iOS

#26

Post by sebastien_b »

userbinator wrote: post #21
sodality2 wrote: post #18

Earlier quoted context omitted.

I can't imagine anyone would disagree with 1024 characters.

"But that doesn't fit in a byte; why not make it 64k instead so it's 2 bytes?" "Why not 1023?" "Even 1023 is too long, I don't think anyone would need that." "What if ?" "How about 32?" Having been in a few meetings that went in that direction, I am not surprised that they couldn't agree on a limit. "Design by committee" at its worst.

I doubt it even went that far - given the size the story mentions (500,000 characters, but isn't clear if they tried smaller), my thinking is the programmer didn't make any checks whatsoever and just thought "no one will type in crazy-large values here, and even if they do it'll just truncate on display" (if that) without consideration on how it might affect memory.

Re: A persistent denial of service vulnerability affecting iOS

#27

Post by Lammy »

rootsudo wrote: post #25
Lammy wrote: post #8

Earlier quoted context omitted.

> all the functions are part of privileged bundles shipped with the OS Luckily a lot of these can be disabled when jailbroken: https://i.imgur.com/KhGmGrf.png

What app is that? I tried to get into cydia and such as of late, and it's a confusing ecosystem, you need to find specific marketplace links from github to browse and then alot of stuff is very legacy and not organized. Would love to jb but it is complicated.

It's iCleaner Pro. Here's the repo you can add in Cydia: https://ib-soft.net/

Re: A persistent denial of service vulnerability affecting iOS

#28

Post by rootsudo »

Lammy wrote: post #27
rootsudo wrote: post #25

Earlier quoted context omitted.

What app is that? I tried to get into cydia and such as of late, and it's a confusing ecosystem, you need to find specific marketplace links from github to browse and then alot of stuff is very legacy and not organized. Would love to jb but it is complicated.

It's iCleaner Pro. Here's the repo you can add in Cydia: https://ib-soft.net/

Thank you! :)

Re: A persistent denial of service vulnerability affecting iOS

#29

Post by mjsweet »

sebastien_b wrote: post #9

There are so many bugs in iOS that are years old and still unfixed. One example is the cellular-data draining bug[1]. The only "solution" for this is to wipe your device, and set it up again, without restoring any backups, at all. Which makes the whole point of backups of the device totally pointless. For a company that spent $6B+ on a (now mostly empty) campus, you'd think they could spare a few $million into proper…

I had to do this last year. Three calls to Apple Support... in the end I just wiped the phone and started over. The first time in 10 years. I was burning through my entire quota in 20 days and then racking up $10 per Gb over the quota with Optus. Very frustrating.

Re: A persistent denial of service vulnerability affecting iOS

#30

Post by bjoli »

sebastien_b wrote: post #24
tshaddox wrote: post #22

Earlier quoted context omitted.

I don’t see any indication that Apple recommends this workaround.

I was told this by Apple when I brought up the problem through their “support” for the cellular drain issue.

For the record, so was I, but by a repair/data-wipe technician.
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